Method for nucleic acid detection by guiding through a nanopore

ABSTRACT

The invention provides a method of detecting a target polynucleotide in a sample comprising: (a) contacting the sample with a guide polynucleotide that binds to a sequence in the target polynucleotide and a polynucleotide-guided effector protein, wherein the guide polynucleotide and polynucleotide-guided effector protein form a complex with any target polynucleotide present in the sample; (b) contacting the sample with a membrane comprising a transmembrane pore; (c) applying a potential to the membrane; and (d) monitoring for the presence or absence of an effect resulting from the interaction of the complex with the transmembrane pore to determine the presence or absence of the complex, thereby detecting the target polynucleotide in the sample.

RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. § 371 ofinternational application number PCT/GB2017/052946, filed Sep. 29, 2017,which claims the benefit of United Kingdom application numberGB1616590.4, filed Sep. 29, 2016, each of which is herein incorporatedby reference in its entirety.

FIELD OF THE INVENTION

The invention relates generally to a method of detecting and/oranalysing target polynucleotides using a transmembrane pore. Theinvention also relates to novel probes and panels of probes for use inthe method and kits for carrying out the method. The method has manyuses. In particular, the method may be used for diagnosis, detection ofpolymorphisms and V(D)J repertoire analysis.

BACKGROUND TO THE INVENTION

There is currently a need for rapid and cheap polynucleotide (e.g. DNAor RNA) sequencing and identification technologies across a wide rangeof applications. Existing technologies are slow and expensive mainlybecause they rely on amplification techniques to produce large volumesof polynucleotide and require a high quantity of specialist fluorescentchemicals for signal detection.

Transmembrane pores (and other nanopores) have great potential asdirect, electrical biosensors for polymers and a variety of smallmolecules. In particular, recent focus has been given to nanopores as apotential DNA sequencing technology.

When a potential is applied across a nanopore, there is a change in thecurrent flow when an analyte, such as a nucleotide, resides transientlyin the barrel for a certain period of time. Nanopore detection of thenucleotide gives a current change of known signature and duration. Inthe strand sequencing method, a single polynucleotide strand is passedthrough the pore and the identities of the nucleotides are derived.Strand sequencing can involve the use of a molecular brake to controlthe movement of the polynucleotide through the pore.

SUMMARY OF THE INVENTION

The present inventors have identified a novel use for the guide RNAs andDNAs and RNA-guided and DNA-guided effector proteins that form part ofthe CRISPR gene editing machinery. The present inventors have designedmodified guide RNA sequences that can be used in conjunction withassociated RNA-guided effector proteins to test for the presence,absence or amount of one or more target polynucleotides in a sample. Thepresent inventors have developed methods of detecting targetpolynucleotides using guide RNAs and RNA-guided effector proteins inconjunction with a transmembrane pore. The methods can be performed in avariety of ways, but have in common that they use guide RNAs andRNA-guided effector proteins to select the target polynucleotide(s) andinvolve the delivery of a complex comprising the target polynucleotide,guide RNA and RNA-guided effector protein to a transmembrane pore. Themethods can be extended to other polynucleotide-guided protein effectorsystems, including the RNA editing system using C2c2. The guidepolynucleotide, such as guide RNA, may be specially adapted for use in ananopore-based detection method.

The methods developed by the present inventors are sensitive and can beused to detect trace amounts of polynucleotide in a sample withoutrequiring a separate separation step to extract the targetpolynucleotide(s) from other components in the sample. Thus, the methodsare simple and do not require complex steps, such as enrichment orpurification steps. Accordingly, the methods are rapid and can be usedto obtain quick results and results from crude and/or “dirty” samples.The methods are therefore particularly useful in diagnostic settingswhere rapid diagnosis is required. The methods are also particularlyuseful in targeting a particular fragment or region of a gene or genome.A key benefit of the methods is that the polynucleotide guided effectorprotein does not actively need to be removed from the targetpolynucleotide prior to measurement of the target or the adaptor. Insome embodiments of the invention, the target polynucleotide may bedetected or characterized whilst still attached to the polynucleotideguided effector protein. In other embodiments of the invention, thepolynucleotide guided effector protein may be automatically removed bythe transmembrane pore during measurement of the target. In someembodiments, the method uses specifically designed guide polynucleotidesto facilitate separation of the target polynucleotide(s) from othercomponents in the sample.

The methods enable the regions of interest of polynucleotide sequence tobe characterized, for example sequenced, in a sample that contains manyother polynucleotide sequences as it inherently includes a separationstep. For example, only genes of interest present in a large genome maybe sequenced. The sequencing can be limited to regions that containSNPs, or to other regions of interest, such as V(D)J regions in T-cells.This improves sensitivity and efficiency, with the desired informationbeing accessed without requiring complicated or time-consumingfragmentation or pull-down sample preparation methods. It also reducesthe time taken perform the nanopore experiment as only the targetpolynucleotide fragments of interest are measured, or an increasedproportion thereof are measured relative to the total polynucleotidefragments in the sample In cases where the amount of non-targetpolynucleotide is in excess to that of the target polynucleotide, thetime taken to detect the target polynucleotide can be significantlyreduced due to the removal of or a reduction in the need to measurenon-target polynucleotides. The methods also benefit from not requiringPCR or other target enrichment approaches.

Accordingly, the present invention provides a method of detecting atarget polynucleotide in a sample comprising:

-   -   (a) contacting the sample with a guide polynucleotide that binds        to a sequence in the target polynucleotide and a        polynucleotide-guided effector protein, wherein the guide        polynucleotide and polynucleotide-guided effector protein form a        complex with any target polynucleotide present in the sample;    -   (b) contacting the sample with a membrane comprising a        transmembrane pore;    -   (c) applying a potential difference across the membrane; and    -   (d) monitoring for the presence or absence of an effect        resulting from the interaction of the complex with the        transmembrane pore to determine the presence or absence of the        complex, thereby detecting the target polynucleotide in the        sample.

Also provided is a method of detecting a target polynucleotide in asample comprising:

-   -   (a) contacting the sample with a guide polynucleotide that binds        to a sequence in the target polynucleotide and a        polynucleotide-guided effector protein, wherein the guide        polynucleotide and polynucleotide-guided effector protein form a        complex with any target polynucleotide present in the sample;    -   (b) contacting the sample with a nanopore;    -   (c) applying a potential difference across the nanopore; and    -   (d) monitoring for the presence or absence of an effect        resulting from the interaction of the complex with the nanopore        to determine the presence or absence of the complex, thereby        detecting the target polynucleotide in the sample.

The invention also provides:

-   -   a guide polynucleotide comprising a nucleotide sequence that        binds to a sequence in the target polynucleotide, a nucleotide        sequence that binds to a polynucleotide guided effector protein        and an adaptor sequence and/or an anchor capable of coupling to        a surface;    -   a panel of two or more guide polynucleotides of the invention;    -   a guide polynucleotide/polynucleotide-guided effector protein        complex comprising a guide polynucleotide of the invention and a        polynucleotide-guided effector protein;

a kit comprising: a polynucleotide-guided effector protein and an anchorcapable of coupling to a surface; and

a method of detecting a target comprising a double strandedpolynucleotide in a sample comprising:

-   -   (a) contacting the sample with a first probe and a second probe,        wherein the first probe and the second probe form a complex with        any target polynucleotide present in the sample, the first probe        binds to a first sequence in the target double stranded        polynucleotide and comprises an anchor capable of coupling to a        surface, and the second probe binds to a second sequence in the        target double stranded polynucleotide and comprises an adaptor        sequence;    -   (b) contacting the sample with a transmembrane pore;    -   (c) applying a potential to the transmembrane pore; and    -   (d) monitoring for the presence or absence of an effect        resulting from the interaction of the complex with the        transmembrane pore to determine the presence or absence of the        complex, thereby detecting the target double stranded        polynucleotide in the sample.

DESCRIPTION OF THE FIGURES

It is to be understood that Figures are for the purpose of illustratingparticular embodiments of the invention only, and are not intended to belimiting.

FIG. 1 shows an example of how an inactivated CRISPR-Cas9 complexbearing an extended CRISPR RNA (crDNA) may be used to contact specificgenomic DNA sequence ‘a’. In this figure, a Cas9 protein A contacts aspecific locus a in genomic DNA B. The CRISPR RNA C bears the sequenceof a, which precedes a ‘PAM’ site D. Cas9 catalyses the melting of a andhybridises to non-target strand a′. The crRNA may also carries asequence bearing partial complementarity to tracrRNA E and an extensionF which enables the hybridisation of an anchoring polynucleotide orpolynucleotide binding protein loaded polynucleotide. The tracrRNA mayalso carry an extension G which enables the hybridisation of ananchoring polynucleotide, or polynucleotide binding protein loadedpolynucleotide. Alternatively, the Cas9 may carry a peptide tag, orpolynucleotide affinity tag, or reactive moiety H, which enables thebinding or pulldown of the protein to a surface for anchorage orpurification. Also shown are the canonical cleavage sites I, J for thewild-type Cas9 nuclease, both of which are inactivated in the ‘dead’Cas9 (dCas9), and one of which is inactivated in the ‘nickase’ mutantsof Cas9, (mutations of residues H10 and D840 in the Streptococcuspyogenes protein).

FIG. 2 shows an alternative method to FIG. 1 in which a CRISPR-Cas9 withzero or one inactivated nuclease sites is bound to a specific locus (asper FIG. 1) and an adapter carrying an enzyme B and sequencecomplementary to sequence a is extended and ligated directly to thetarget DNA. Panel C shows the double-strand break in the target inducedat one or both sites D and E by the active or partially active Cas9nuclease. Panel F shows the dissociation of the CRISPR-Cas9 complexinduced by binding of species B to the displaced strand of theCRISPR-Cas9 complex. Panel G shows the effect of extending the 3′ end ofspecies B in the presence of a polymerase-exonuclease such as E. coliDNA polymerase I and ligase such as E. coli DNA ligase.

FIG. 3 shows how an enzyme-loaded adaptor (‘Y-adaptor’), species A, maybe hybridised to a crRNA-tracrRNA hybrid, species B, bearing anappropriate 3′ extension. Species A comprises: an oligonucleotide C withpartial complementarity a* to the 3′ extension of species B, and a 5′extension for loading of an enzyme D; an oligonucleotide E bearingpartial complementarity to species C. Oligonucleotide Species Bcomprises: an oligonucleotide F carrying: sequence S1, the protospacersequence of the crRNA, partial complementarity to tracrRNA G, and a 3′extension of sequence a, complementary to sequence a*.

FIG. 4 shows how an anchoring species A, such as an oligonucleotidecarrying a cholesterol moiety, may be hybridised to a crRNA-tracrRNAhybrid, species B, bearing an appropriate 3′ extension. All parts aresimilar to FIG. 3 except: sequence S2 is a protospacer sequence uniqueto species B, and targeting a different sequence to the hybrid shown inFIG. 3; sequence b, a 3′ extension to the crRNA that is complementary tosequence b*, on the anchoring species A. Species A carries an anchoringmoiety C, such as a cholesterol or biotin or desthiobiotin.

FIG. 5 shows how a double-stranded DNA target A may be differentiatedfrom a non-specific DNA B by means of recognition by a CRISPR-Cas9complex C.

FIG. 6 is identical to FIG. 5, except that the specific and non-specificDNA in a mixture may be derivatised with an adapter moiety A may be usedfor capture of target and non-target DNA by a nanopore.

FIG. 7 is identical to FIG. 6, except that the adapter moiety A maycarry an polynucleotide binding protein B used to control the movementof target and non-target DNA through a nanopore.

FIG. 8 shows an example in which CRISPR-Cas9 complexes (A, B) directedagainst two adjacent loci on a target DNA C may be used to positivelyidentify a sample. Complex A contains a crRNA bearing an enzyme-loadedextension, as per FIG. 3. Complex B contains a crRNA complex bearing ananchoring extension, as per FIG. 4. DNA bearing a locus that bindsComplex B binds to surface D such as a tri-block polymer membrane. Theenzyme bound to Complex A may control the movement of a barcoded DNAanalyte E through a nanopore. Following the removal of non-specificanalytes (including species with no target loci, F) from solution, viaflushing the system, only entity G bearing the two loci will bedetected, and not entities F, H or I.

FIG. 9 shows an example in which an inactive Cas9 (‘dCas9’) bearing anextension containing an anchoring moiety may be used to enrich anddetermine the sequence of a target analyte via polynucleotide bindingprotein controlled translocation through a nanopore. In this example, anenzyme-bound adapter moiety is ligated to one or both ends of all DNA insolution. Only DNA containing the target locus binds the anchoring dCas9complex.

FIG. 10 shows a DNA analyte with a ligated, enzyme-bound adapter thatmay be used to control the movement of a DNA analyte through a nanopore.

FIG. 11 shows a DNA analyte with bound enzyme, similar to FIG. 10, inwhich the translocation of the enzyme may be temporarily stalled by aCRISPR-dCas9 complex bound to a specific locus.

FIG. 12 shows a method for detection of dCas9 bound to a targetpolynucleotide analyte in which both strands of the target analyte andthe bound dCas9 are translocated through a nanopore, where the nanoporebears a constriction that permits passage of the target analyte andbound dCas9, and in which the dCas9 produces a characteristic deflectionin the ionic current measured through the nanopore.

FIG. 13 shows a method for detection of dCas9 bound to a targetpolynucleotide analyte in which both strands of the target analyte aretranslocated through a nanopore, but the constriction of the nanoporeprevents translocation of the bound dCas9 and produces a characteristicdeflection or dwell-time in the ionic current measured through thenanopore.

FIG. 14 shows a method for the detection of dCas9 bound to a targetpolynucleotide analyte in which the target analyte is derivatised withan polynucleotide binding protein free adaptor, as per FIG. 6, and inwhich one of the two strands of the polynucleotide analyte istranslocated through the nanopore, and in which the dCas9 bound to thetarget analyte produces a characteristic deflection or dwell-time in theionic current measured through the nanopore.

FIG. 15 shows a method for the sequencing of a target analyte with bounddCas9 in which the target analyte is derivatised with a polynucleotidebinding protein bound adaptor, as per FIG. 7, and in which translocationof one of the two strands of the polynucleotide analyte is controlledthrough the nanopore by the polynucleotide binding protein. In thisexample, the dCas9 bound to the target analyte may produce acharacteristic stall in the translocation of the polynucleotide bindingprotein, and thus in the ionic current measured through the nanopore.

FIG. 16 shows a method for the identification of a target DNA anchoredto a membrane, as per FIG. 8, via an extended CRISPR-dCas9 bearing acholesterol moiety, as per FIG. 4, and identified by controlled movementof a barcoded, polynucleotide binding protein loaded oligonucleotideanalyte hybridised to an extended CRISPR-dCas9 complex, as per FIG. 3,and which binds to a locus adjacent to the cholesterol-extendedCRISPR-dCas9.

FIG. 17 shows a derivative of FIG. 16 in which the anchoring moiety maybe, for example, biotin or desthiotin, and the anchoring moiety may bindto a streptavidin-derivatised bead or nanoparticle.

FIG. 18 shows an example of a target DNA that is anchored to a membranevia a cholesterol-extended CRISPR-dCas9 complex that binds to a known orcommon locus, and in which the same target DNA contains a number ofunknown sequences whose presence or absence is determined byenzyme-extended CRISPR-dCas9 complexes. In this example, eachenzyme-extended CRISPR-dCas9 complex carries a unique barcode that maybe used to positively identify the presence or absence of the loci incombination, as per FIG. 16. The target DNA could also be directlycoupled to the membrane rather than via the cholesterol-extendedCRISPR-dCas9 complex.

FIG. 19 shows an example polynucleotide, lambda phage DNA, and theposition of a specific target locus A that is 2,855 bp from the end ofthe genome.

FIG. 20 shows the target locus of FIG. 19, with bound CRISPR-dCas9bearing a cholesterol extension, fragmented randomly into 1-3 kbsegments, with each segment bearing an polynucleotide binding proteinloaded Y-adaptor at either or both ends for determining the sequence ofthe target polynucleotide. The assembly is anchored to a membranesurface via the cholesterol moiety.

FIG. 21 shows a coverage plot of sequence data aligned against a phagelambda reference from an experiment in which phage lambda DNA wasrandomly fragmented into 1-3 kb segments; enzyme-Y-adaptor was ligatedto the fragmented DNA; and a cholesterol-extended CRISPR-dCas9 was boundto the target shown in FIG. 19. The coverage plot shows enrichment ofthe specific locus A in the expected location (2,855 bp from the end ofthe lambda phage genome). The top panel shows the alignments accumulatedfrom the forwards (B) and reverse (C) read directions, and the bottompanel shows the aggregate of the forwards and reverse orientations.

FIG. 22 shows an example trace of the nanopore current signaturedetected by polynucleotide binding protein controlled translocation of atarget DNA bearing a bound, cholesterol-extended dCas9 at the locusshown in FIGS. 19 and 20. In this example, the dCas9 transiently stallsthe translocation of the enzyme. The current traces comprises: open porelevel A, leader signature B, target analyte signature C, and stall D.

FIG. 23 shows an example trace of the nanopore current signaturedetected by enzyme-controlled movement of a barcoded oligonucleotide onan enzyme-extended dCas9, as per FIG. 16. The current trace comprises:open pore level A, leader signature B, and barcode signature C.

FIG. 24 illustrates how guide polynucleotide/polynucleotide-guidedeffector proteins may be used to bring polynucleotide targets to amembrane comprising a transmembrane pore. The unbound polynucleotidesmay be flushed away prior to application of a transmembrane potentialand detection of the polynucleotide/polynucleotide-guided effectorprotein/target polynucleotide complex using the transmembrane pore.

FIG. 25 shows examples of how an adaptors and leader sequence may beattached to guide RNA.

FIG. 26 shows how the method of the invention may be used to detect thepresence or absence of SNPs using a guidepolynucleotide/polynucleotide-guided effector protein comprising amembrane anchor to tether a polynucleotide to a membrane and guidepolynucleotide/polynucleotide-guided effector proteins specific fordifferent SNPs and comprising barcoded adaptors to distinguish betweenthe SNPs.

FIG. 27 shows how a pair of guide polynucleotides/polynucleotide-guidedeffector proteins can be used to obtain a polynucleotide fragmentcomprising a region of interest (ROI). The first guidepolynucleotide/polynucleotide-guided effector protein could have itsnuclease activity disabled such that it acts to stall a polynucleotidebinding protein as shown in FIG. 11, enabling the region of interest tobe characterized using a transmembrane pore.

FIG. 28A shows the immobilisation of a target DNA analyte (A) comprisingan enzyme-bound Y-adaptor (B) ligated to both ends, and tethered at bothends on a membrane (C) surface via oligonucleotides each bearing acholesterol moiety (D). A bound CRISPR-dCas9 (E) bearing a cholesterolanchor (F), tethers the analyte to the membrane in a third position.This figure shows the system before the addition of MgATP to initiateenzyme translocation on DNA. FIG. 28B shows the immobilisation of atarget DNA analyte (A) comprising an enzyme-bound Y-adaptor (B) ligatedto both ends, each bearing a cholesterol moiety (D). A boundCRISPR-dCas9 (E) bearing an affinity tag such as a biotin moiety (F),tethers the analyte to a bead (C) such as streptavadin. This Figureshows the system before the addition of MgATP to initiate enzymetranslocation on DNA. FIG. 28C shows the immobilisation of a target DNAanalyte (A) comprising an enzyme-bound Y-adaptor (B) ligated to one endbearing a cholesterol moiety (D). The other end has a hairpin (G). Abound CRISPR-dCas9 (E) bearing an affinity tag such as a biotin moiety(F), tethers the analyte to a bead (C) such as streptavadin. This Figureshows the system before the addition of MgATP to initiate enzymetranslocation on DNA.

FIG. 29 shows the system introduced by FIG. 28 upon the addition ofMgATP. The translocation of enzyme towards the CRISPR-dCas9 complex ishalted upon encounter of the CRISPR-dCas9 complex (A).

FIG. 30 shows the system introduced by FIG. 29 upon the application of apotential across the membrane, and capture of the end of the targetanalyte by a nanopore (A).

FIG. 31 shows the system introduced by FIG. 30 whereupon the potentialapplied to the analyte has released the enzyme bound to the CRISPR-dCas9complex and the enzyme has resumed translocation (A).

FIG. 32 shows an example trace, ˜2350 secs after the addition of MgATP,comprising an initial, pre-dCas9 translocation event (B), stalling (C),and resumption of translocation (D). The resumption from the stall ishighlighted and expanded (E).

FIG. 33 is a schematic of a double stranded DNA strand encountering apore which is only big enough for a single strand of DNA to fit through.The complementary strand is stripped away by the pore as the firststrand passes through.

FIG. 34 shows a current vs time plot of a DNA strand translocatingthrough a Nanopore. The trace begins at the open pore level, A, whenthere is no DNA in the pore. A double stranded DNA strand with anadapter at each end then encounters the pore and begins to translocate.The pore is too small for double stranded DNA to pass through so only asingle strand translocates as per FIG. 33. The translocation of the DNAproduces a characteristic signal (region B) and then returns to the openpore level, A. The events typically last less than 0.5 s. The lowerpanel is a zoomed in view of the upper panel.

FIG. 35 shows the same experiment as FIG. 34 except that the DNA strandhas a dCas9 enzyme bound to it, as illustrated in FIG. 14. Long pauseslasting 10 s of seconds are observed at a current level associated withDNA in the pore. Some of these events only return to the open pore levelwhen the potential is reversed.

FIG. 36 shows the experiment as FIG. 34 except that the DNA strand has adCas9 enzyme bound to it, as illustrated in FIG. 14. It shows an eventin which the strand translocates and the signal returns to the open porelevel, A. The second and third panels are zoomed in views of the firstpanel, with the second showing the beginning of the event and the thirdshowing the end. It can be seen from this trace that the signal has thesame characteristic pattern as in FIG. 34, but with a new long pauselevel in it, C. This demonstrates that the dCas9 bound to the DNA strandis causing a modification of the signal observed with DNA alone.

FIG. 37 shows an example current trace of a double stranded DNA strandpassing intact through a pore large enough to accommodate it. From theopen pore current, A, the current drops to a lower level as the DNApasses through it, B, and then returns to the open pore level.

FIG. 38 shows an example current trace of a double stranded DNA strandpassing intact through a pore large enough to accommodate it. In thiscase, the DNA has a protein bound to it as shown in FIG. 12. Here thereis an extra deflection in the current coming from the DNA level whichrepresents the protein translocating (C).

FIG. 39 shows an example current trace of a double stranded DNA strandpassing intact through a pore large enough to accommodate it, whereinmultiple proteins are bound to the DNA. Each protein causes a separatedeflection to the current.

FIG. 40 shows an example current trace of a double stranded DNA strandpassing intact through a pore large enough to accommodate it, whereinmultiple proteins are bound to the DNA (at different positions to thosein FIG. 39) and the proteins have been modified or decorated so thatthey produce different signals when they pass through the pore.

FIG. 41 shows an example method for the enrichment and detection orsequencing of a dCas9-contacted target A to a bead surface B, with crRNAC and tracrRNA bearing a 5′ DNA extension D with sequence a. Target Amay be any size, ranging from tens of nucleotides to greater thanmegabases in length. B may for instance be a bead surface (in bulksolution or in column format) or membrane. Attachment to B is mediatedby oligonucleotide E, bearing sequence a′ complementary to the extensionof D, which bears a chemical moiety such as biotin that enablesattachment to bead B if B is coated with a protein such as streptavidin.Non-target DNA may subsequently be washed away from B. Enzymatic orclick chemistry ligation of adapter F to blunt or complementary ends oftarget A may be achieved while the target is bound to the bead, withexcess adapter washed away, to yield target-dCas9-bead assembly G.Sequencing or detection of the target A is then achieved by deliveringassembly G to a flowcell containing membrane H, and cholesterol-modifiedoligonucleotide tether I, which hybridises to adaptor F via sequence t′,complementary to t. Assembly G may be delivered to the membrane bygravity, or by an applied magnetic field if for instance bead B isparamagnetic.

FIG. 42 shows an example coverage plot showing the enrichment of all 16S (rrs) genes from a total E. coli genomic sample, using a crRNA probedirected against the rrsH gene (coordinates 223771-225312 of E. coliK-12, strain MG1655, peak i). A, top shows a plot of coverage versusposition for forwards (positive numbers) and reverse (negative numbers)direction reads. Seven target peaks, i to vii, are indentified, whichare over-represented against background B. A, bottom shows theaggregation of forwards and reverse direction reads. C shows a histogramof the read length of all reads that successfully mapped to thereference, normalised to the number of bases mapped in each bin. D showsthe seven expected binding locations of the single probe used in thepulldown. Peak vii is located at a target sequence that is a canonical‘off-target’ site, but bears 19 out of 20 matches to the probe sequence.

FIG. 43 shows the effect of applying a heat stress, followed bysubsequent SPRI-bead cleanup and bead-based dCas9 pulldown to adCas9-contacted DNA sample on the proportion of target vs. non-targetmolecules bound, as determined by nanopore sequencing.

FIG. 44 shows an example of a sequential ‘pull-down’ and ‘toeholdelution’ method that exploits two distinct oligonucleotide extensions,sequences [a−c] and d, from the tracrRNA and crRNA respectively of adCas9-contacted target molecule A, and may be used to select for thepresence of the tracrRNA and crRNA (or vice versa), sequentially.Oligonucleotide B, bearing sequence a′−b′, partly complementary totracrRNA extension a, is first bound to purification surface C; A isincubated with [B+C] and any non-target DNA washed away. OligonucleotideD, bearing sequence [a+b], fully complementary to oligonucleotide B,when incubated with [A+B+C], will displace oligonucleotide B from thetracrRNA extension of A by a phenomenon known as ‘toehold displacement’,releasing A from [B+C]. A may either be adapted and delivered to aflowcell for nanopore sequencing or detection, as outlined in FIG. 41,or may then be bound to a second type of surface E, bearing a duplexoligonucleotide F with overhang d′ that is complementary to the crRNAextension G (sequence d), to yield F. F may also be adapted andsequenced or detected as outlined in FIG. 41. Surfaces C and E may be abead (whether in bulk or column format) or membrane.

FIG. 45 shows the combinatorial effect of heat stress (55° C., 5 min),SPRI purification (performed after heat stress, where applicable; 1×),and the toehold displacement method (performed after bead capture), froma pulldown of the 16S rrs genes using a single crRNA probe, as describedin Example 7. A, control with no heat stress, SRRI or toehold. B, SRRIonly. C, heat stress only. D, heat stress and SPRI. E, toehold only. F,SPRI and toehold. G, heat stress and toehold. H, heat stress, SPRI andtoehold. Each panel (A through H) shows an example E. coli coverageplot, similar to that shown in FIG. 42.

FIG. 46 compares pulldowns performed with wild-type or ‘enhancedspecificity’ mutant of dCas9, as described in Example 8. Panel A shows acontrol experiment in which the dCas9 mutant variant, in an otherwisewild-type background, was used to pull out the E. coli rrs 16S genes, asdescribed in FIG. 42 and Example 6. Peaks are as identified in FIG. 42.Panel B shows an equivalent experiment in which the wild-type dCas9mutant variant was replaced with the ‘enhanced specificity’ dCas9mutant, D10A/H840A/K848A/K1003A/R1060A. Peaks C and D also correspondsto peak vii of FIG. 42, and correspond to the rrsD gene, which carries amismatch at position −2 relative to the PAM.

FIG. 47 shows coverage plots from nanopore DNA sequencing runs ofpulldowns performed with catalytically dead (dCas9, A) or live (B) Cas9,as described in Example 9. Panel A shows a control experiment in whichthe dCas9 mutant variant, in an otherwise wild-type background, was usedto pull out the E. coli rrs 16S genes, as described in FIG. 42 andExample 6. The incubation temperature in this experiment was 30° C.Panel B shows a similar pulldown experiment in which the dCas9 mutantwas replaced with catalytically active Cas9. The incubation temperaturein this experiment was 37° C. * denotes an additional peak attributableto the higher incubation temperatures used in this experiment comparedwith Example 6. Panels C and D show coverage plots for the dCas9 andlive Cas9 pulldowns in which the coverage is grouped by thedirectionality of the read; positive numbers denote forwards reads,while negative numbers denote reverse reads.

FIG. 48, A shows a bead-target conjugate, similar to that shown in FIG.41, but additionally containing a barcode adapter B between theenzyme-loaded adapter and the target molecule C. Other components are asdescribed in FIG. 41. Panel D shows coverage plots from a single 6-hoursequencing run that contained seven individually-barcoded samples, NB01through NB07. Each barcode is associated with a different set of crRNAprobes, and therefore a different target region of the E. coli genome,as described in the text of Example 10. Probe combinations are listed inthe text of Example 10.

FIG. 49 shows three example workflows involving the attachment ofadapters to a captured target analyte, while the analyte is bound viadCas9 to beads. A, the enzyme-free detection of dCas9, via the ligationof an enzyme-free adapter to the ends of a captured target analyte boundto beads; B, the enrichment of target by the ligation of PCR adapters,followed by PCR amplification of the target, as described above, torelease, amplify and sequence target from beads; and C, the sequentialligation of 1D² barcode adapters, followed by sequencing adapters, forhigh-accuracy nanopore sequencing, while dCas9 is bound to the target,and the target bound to beads.

FIG. 50 shows an example workflow, described in Example 11, for therapid enrichment of target from high-molecular weight DNA, bytransposase-mediated shearing of the DNA, while concomitantly adding asticky end for adapter ligation by click chemistry. dCas9 is then boundto the sheared DNA, as described in Example 11; off-target effects areminimised by a stress step, as previously described in Example 6, andsequencing adapters ligated via click chemistry. This workflow makes useof the Oxford Nanopore Technologies SQK-RAD003 kit, with the insertionof a Cas9 binding and bead capture step between the transposasefragmentation and adapter attachment steps, as described in Example 11.

FIG. 51 shows a hypothetical example method for the enrichment anddetection or sequencing of a Cpf1 or dCpf1-contacted target A to a beadsurface B, with crRNA bearing a 5′ DNA extension C with sequence a.Target A may be any size, ranging from tens of nucleotides to greaterthan megabases in length. B may for instance be a bead surface (in bulksolution or in column format) or membrane. Attachment to B is mediatedby oligonucleotide E, bearing sequence a′ complementary to the extensionof C, which bears a chemical moiety such as biotin that enablesattachment to bead B if B is coated with a protein such as streptavidin.Non-target DNA may subsequently be washed away from B. Enzymatic orclick chemistry ligation of adapter F to blunt or complementary ends oftarget A may be achieved while the target is bound to the bead, withexcess adapter washed away, to yield target-Cpf1-bead assembly G.Sequencing or detection of the target A is then achieved by deliveringassembly G to a flowcell containing membrane H, and cholesterol-modifiedoligonucleotide tether I, which hybridises to adaptor F via sequence t′,complementary to t. Assembly G may be delivered to the membrane bygravity, or by an applied magnetic field if for instance bead B isparamagnetic.

FIG. 52 shows a hypothetical example in which a ‘paired-adaptor’pulldown is performed, such as that described in Example 13. A targetDNA analyte A (bearing target sequences y and z) is mixed with anon-target DNA analyte B at varying concentrations of A ranging fromzero to hundreds of nanograms. C as described in Example 8 is adCas9-tracrRNA-crRNA complex bearing a DNA extension on the crRNA thatcarries a nanopore sequencing adapter and optional barcode sequence b. Dis a dCas9-tracrRNA-crRNA complex bearing a DNA extension on the crRNAthat carries a sequence t that enables the crRNA to be tethered to asurface. Addition of species C and D to the mixture of A and B allowsdetection of A in the background of B. Only target molecules bearingsequences y and z are both tethered via cholesterol modifiedoligonucleotide E (with sequence t′ complementary to the extension t ofD) to membrane surface F and carry an enzyme adapter that permitsdetection of the target analyte. Nanopore capture of G is thereforeenhanced over capture of H. Capture of G and H by nanopore J is measuredelectronically. K shows an example nanopore current trace punctuated bycapture event L1 and open-pore current L2. The frequency of L1 isdependent on the concentration of species G on the membrane and thebackground level of H in solution. M shows a hypothetical plot of thefrequency of event L1 against the concentration of target analyte A. Nshows the level of background capture of species ‘G’ from solution andthus is the ‘false-positive’ rate.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that different applications of the disclosedproducts and methods may be tailored to the specific needs in the art.It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments of the invention only, andis not intended to be limiting.

In addition as used in this specification and the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontent clearly dictates otherwise. Thus, for example, reference to “apolynucleotide” includes two or more polynucleotides, reference to “ananchor” refers to two or more anchors, reference to “a helicase”includes two or more helicases, and reference to “a transmembrane pore”includes two or more pores and the like.

All publications, patents and patent applications cited herein, whethersupra or infra, are hereby incorporated by reference in their entirety.

Methods

The invention provides a method of detecting a target polynucleotide ina sample comprising: (a) contacting the sample with a guidepolynucleotide that binds to a sequence in the target polynucleotide anda polynucleotide-guided effector protein, wherein the guidepolynucleotide and polynucleotide-guided effector protein form a complexwith any target polynucleotide present in the sample; (b) contacting thesample with a membrane comprising a transmembrane pore; (c) applying apotential difference across the membrane; and (d) monitoring for thepresence or absence of an effect resulting from the interaction of thecomplex with the transmembrane pore to determine the presence or absenceof the complex, thereby detecting the target polynucleotide in thesample. Step (a) and (b) may be carried out simultaneously orsequentially in either order.

The method may comprise (a) contacting the sample with a guidepolynucleotide that binds to a sequence in the target polynucleotide anda polynucleotide-guided effector protein to form a complex, wherein thesample is in contact with a membrane comprising a transmembrane pore andwherein a potential is applied to the transmembrane pore; and (b) takingone or more measurements as at least a portion of the complex moves withrespect to the transmembrane pore to detect the presence or absence ofthe complex, thereby detecting the target polynucleotide in the sample.

In some embodiments, the method comprises: (a) contacting the samplewith a guide polynucleotide that binds to a sequence in the targetpolynucleotide, a polynucleotide-guided effector protein and a membranecomprising a transmembrane pore; (b) applying a potential differenceacross the membrane; and (c) measuring the ion flow passing through thetransmembrane pore, or other signal resulting from the interaction ofthe sample, guide polynucleotides and polynucleotide-guided effectorproteins with the transmembrane pore, to determine the presence orabsence of a complex comprising the guide polynucleotide,polynucleotide-guided effector protein and the target polynucleotide,thereby detecting the target polynucleotide in the sample. Measurementof ion flow may comprise measurement of the current flow through thepore.

The methods can be carried out in a number of different ways. Themethods can be used to perform a variety of different applications. Themethods may be used, for example, to determine the presence or absenceof a single target polynucleotide, or of a number of targetpolynucleotides. The methods may be quantitative. For example, theamount (such as the concentration) of the target polynucleotide presentin a sample may be determined using a method of the invention and/orrelative amounts of different polynucleotides present in a sample may bedetermined. The methods can provide further information about a targetpolynucleotide, such as the presence or absence of a polymorphism and/orthe identity of a polymorphism.

The method may comprise determining whether an adaptor attached to theguide polynucleotide interacts with the transmembrane pore. The methodmay be carried out such that guide polynucleotides comprising adaptorsthat are not bound to the target polynucleotide do not interact with thetransmembrane pore. Typically such unbound guide polynucleotides arewashed away before a transmembrane potential is applied to the membrane.The target polynucleotide may be tethered to a surface, for example tothe membrane, to prevent bound guide polynucleotides comprising adaptorsfrom being washed away. The target polynucleotide may have a tether,such as a membrane anchor, attached to it directly, for example, to oneof its ends. Alternatively, a second guidepolynucleotide/polynucleotide-guided effector protein which comprises atether, such as a membrane anchor, may be used to tether the targetpolynucleotide to the surface, for example to the membrane.

The surface to which the target polynucleotide is tethered may be abead.

The adaptor is typically unique to the target polynucleotide andproduces a distinct signal on interacting with a transmembrane pore.Multiple guide polynucleotides, each selective for a different targetpolynucleotide and having a different adaptor may be added to the sampleto detect and/or quantify different target polynucleotides on the basisof the different signals caused by the different adaptors interactingwith the transmembrane pore. In this embodiment, the adaptors may beconsidered to comprise barcodes.

The method may use multiple guide polynucleotides that bind to differentpolynucleotide sequences. The different polynucleotide sequences may,for example, be different sequences in the same target polynucleotide(e.g. different portions of the target polynucleotide), sequences ofdifferent target polynucleotides or alternative sequences within atarget polynucleotide, such as sequences that encompass polymorphisms,for example single nucleotide polymorphisms (SNPs).

In some embodiments, the method may comprise further characterizing thetarget polynucleotide. For example, the method may comprise sequencingall or part of the target polynucleotide.

In some embodiments, the method may comprise detecting the presence,absence or amount of a target polynucleotide using two or more guidepolynucleotides and/or two or more polynucleotide-guided effectorproteins which bind to different regions of the target polynucleotide,wherein binding of two different guidepolynucleotide/polynucleotide-guided effector proteins to the targetpolynucleotide results in a detectable signal, for example a detectablecurrent change, through a transmembrane pore if the targetpolynucleotide is present in the sample. The signal may becharacteristic of an adaptor in one of the guidepolynucleotides/polynucleotide-guided effector complexes, with thesignal only or primarily being observed when that guide polynucleotideis “linked” to a second guide polynucleotide/polynucleotide-guidedeffector protein comprising a membrane anchor, and this “linkage” occurswhen both guide polynucleotides/polynucleotide-guided effector proteinsare bound to the target polynucleotide. In other words, the targetpolynucleotide serves to “link” the guidepolynucleotides/polynucleotide-guided effector complex comprising anadaptor to the guide polynucleotides/polynucleotide-guided effectorcomplex comprising a membrane anchor. In the embodiment wherein thepolynucleotide-guided effector protein comprises a membrane anchor,attachment may be via the protein itself, for example by use of astrep-tag/flag-tag/his-tag.

In some embodiments, the method may comprise selectively characterizing,for example sequencing, target polynucleotides using a transmembranepore by marking each target polynucleotide with a guidepolynucleotide/polynucleotide-guided effector protein complex specificfor the target polynucleotide such that the target polynucleotide can beselectively sequenced without needing to separate the targetpolynucleotide from other polynucleotides in the sample prior tocontacting the sample with the transmembrane pore.

For example, the guide polynucleotide/polynucleotide-guided effectorprotein complex may be tagged with a membrane anchor so that only targetpolynucleotides are tethered to the membrane. Other polynucleotides inthe sample may be washed away. Alternatively, a polynucleotide bindingprotein capable of moving along a polynucleotide may be bound to the endof the polynucleotides in the sample, for example using techniques knownin the art, and the polynucleotide binding protein may be caused to movealong the polynucleotides after complex formation, for example by addinga cofactor necessary for movement of the polynucleotide binding protein.In this embodiment, the bound guide polynucleotide/polynucleotide-guidedeffector protein complex stalls the polynucleotide binding protein onthe target polynucleotide, whilst the polynucleotide binding protein isprocessed off the ends of non-target polynucleotides. Then, when thetransmembrane potential is applied, the force of the potential and thecontact with the pore displaces the bound guidepolynucleotide/polynucleotide-guided effector protein complex from thetarget polynucleotides so that the target polynucleotide translocatesthrough the pore. The non-target polynucleotides to which nopolynucleotide binding protein is bound pass through the pore so rapidlythat no signal is detected, or so that any signal obtained can easily bediscriminated from signals resulting from the interaction of the targetpolynucleotide with the pore. The 3′-terminated strands of thepolynucleotides in the sample, including both target and non-targetpolynucleotides, may be degraded, for example using an exonuclease. Inthis way the target polynucleotide can be selectively characterized, forexample sequenced. The polynucleotide binding protein may be caused tomove along the polynucleotides by adding a cofactor, such as ATP oranother nucleoside for example and γsGTP.

In another embodiment, the polynucleotide-guided effector protein can beused to cut the polynucleotide at a selected point. This may be used tolimit the information, such as sequence information, obtained by themethod about a region of interest. For example, twopolynucleotide-guided effector proteins with nuclease activity may beused to obtain a polynucleotide fragment of interest as shown in FIG.27. As an alternative, a modified polynucleotide-guided effector proteinhaving inactivated or disabled nuclease activity may be used to stall apolynucleotide binding protein as described above and a secondpolynucleotide-guided effector protein may be used to truncate thefragment being characterized. This embodiment is, for example,particularly useful in V(D)J repertoire analysis applications.

Further, in some embodiments, the guidepolynucleotide/polynucleotide-guided effector protein complex tags orlabels the target polynucleotide such that the effect of the guidepolynucleotide/polynucleotide-guided effector protein complex on thecurrent passing through the pore can be used to determine the presenceor absence of, quantify or identify the target polynucleotide.

For example, the guide polynucleotide or polynucleotide-guided effectorprotein may be attached to an adaptor that may be used to identify atarget polynucleotide tagged with a membrane anchor because the adaptorwill only interact with the transmembrane pore when it is bound to thetarget polynucleotide tethered to the membrane. Unbound guidepolynucleotides and polynucleotide-guided effector proteins may bewashed away. Multiple guide polynucleotides, each selective for adifferent target polynucleotide and having a different adaptor may beadded to the sample to detect and/or quantify different targetpolynucleotides on the basis of the different signals caused by thedifferent adaptors interacting with the transmembrane pore.

Alternatively, the guide polynucleotide/polynucleotide-guided effectorprotein complex bound to the target polynucleotide may produce adetectable signal when the target polynucleotide passes through atransmembrane pore. Where the transmembrane pore is too small to allowthe passage of the guide polynucleotide/polynucleotide-guided effectorprotein, for example a pore that allows the passage of a single strandedbut not a double-stranded polynucleotide, the movement of thepolynucleotide through the pore is blocked when the guidepolynucleotide/polynucleotide-guided effector protein reaches the pore.This affects the current passing through the pore and allows thepresence of the guide polynucleotide/polynucleotide-guided effectorprotein/target polynucleotide complex to be detected. For example, theguide polynucleotide/polynucleotide-guided effector protein complex maybe stripped off the target polynucleotide by the force of the pore andapplied potential (as the target polynucleotide is pulled through thepore by the applied potential the guidepolynucleotide/polynucleotide-guided effector protein complex is broughtinto contact with the pore and the continued pull on the targetpolynucleotide forces the guide polynucleotide/polynucleotide-guidedeffector protein complex against the pore such that the guidepolynucleotide/polynucleotide-guided effector protein complex is forcedoff (i.e. is caused to unbind from) the target polynucleotide), causinga detectable stutter in the current. Two or more guidepolynucleotide/polynucleotide-guided effector protein complexes bindingto different parts of a target polynucleotide may be used in the method.When each of the bound polynucleotide/polynucleotide-guided effectorprotein complexes reaches the pore it will cause a stutter. Thusmultiple guide polynucleotide/polynucleotide-guided effector proteincomplexes may be used to identify a target polynucleotide. For example,one or more guide polynucleotide may be designed to bind to the targetpolynucleotide only if a particular polymorphism is present in thetarget polynucleotide. The number of stutters observed as thepolynucleotide passes through the pore, or the presence or absence of aparticular stutter as the polynucleotide passes through the pore mayindicate the presence or absence of the polymorphism.

When the transmembrane pore is sufficiently large to allow the passageof double stranded polynucleotides and bound guidepolynucleotide/polynucleotide-guided effector protein complex, thepassage of the double stranded polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complex throughthe pore will produce a recognisable signal when the guidepolynucleotide/polynucleotide-guided effector protein complex passesthrough the pore. Thus one or more guidepolynucleotide/polynucleotide-guided effector protein complex may beused to identify a target polynucleotide. For example, a guidepolynucleotide may be designed to bind only if a particular polymorphismis present in the target polynucleotide. The number of signalsattributable to bound guide polynucleotide/polynucleotide-guidedeffector protein complexes observed as the target polynucleotide passesthrough the pore, or the presence or absence of a particular signal asthe target polynucleotide passes through the pore may indicate thepresence or absence of the polymorphism. Nanopores that allow thepassage of double stranded polynucleotides and boundpolynucleotides/polynucleotide-guided effector proteins include, forexample, nanocapillaries. Hence, in this embodiment the pore may not becontained in a membrane. One or more of the guide polynucleotide,polynucleotide-guided effector protein and/or target polynucleotide aretypically modified to enable the method to be carried out. Thus, theinvention also provides modified guide polynucleotides,polynucleotide-guided effector proteins, guidepolynucleotide/polynucleotide-guided effector protein complexes, andpanels of such polynucleotide guides and effector molecules suitable foruse in the invention.

The method may further comprise determining the amount of the targetpolypeptide or one or more characteristics of the target polynucleotide.The one or more characteristics are typically selected from (i) thelength of the target polynucleotide, (ii) the identity of the targetpolynucleotide, (iii) the sequence of the target polynucleotide, (iv)the secondary structure of the target polynucleotide and (v) whether ornot the target polynucleotide is modified.

Step (a) may further comprise contacting the sample with beads (e.g.microparticles) to which one or more components of the complex can bind.Alternatively, one or more of the components used in (a), e.g. thetarget polynucleotide, the guide polynucleotide or thepolynucleotide-guided effector protein may be prebound to beads (e.g.microparticles).

The sample may be provided in an aqueous medium or alternatively thesample may be added to an aqueous medium containing thepolynucleotide-guided effector protein and the guide polynucleotide. Theaqueous medium will typically comprise ions to provide ion flow throughthe transmembrane pore upon application of a potential difference acrossthe membrane. The aqueous medium will also typically comprise a buffer.The aqueous medium typically has a pH in the range of 6 to 9 and/or anion concentration in the rage of from 100 to 200 mM salt, such as NaCl.

The bead is typically denser than the aqueous medium and sink throughthe medium to contact the membrane, thus effectively enhancing theconcentration of the species attached to the anchor at the membranesurface.

In the method, the applied potential may be a voltage potential.Alternatively, the applied potential may be a chemical potential. Anexample of this is using a salt gradient across an amphiphilic layer. Asalt gradient is disclosed, for example, in Holden et al., J Am ChemSoc. 2007 Jul. 11:129(27):8650-5.

In embodiments where displacement of the bound guidepolynucleotide/polynucleotide-guided effector protein complex is notrequired, the guide polynucleotide and/or effector protein may becross-linked to the target polynucleotide.

In the methods of the invention, the guidepolynucleotide/polynucleotide-guided effector protein may be replaced bya probe that binds to a double-stranded polynucleotide. The probe may ormay not be associated with an enzyme. For example, the probe may be aRecA-coated probe, a peptide nucleic acid (PNA), a bridged nucleic acid(BNA), a locked nucleic acid (LNA), gamma PNA, triplex DNA or amorpholino probe. The probe typically comprises a single stranded regioncomplementary to a sequence in the target polynucleotide. The probe maycomprise a double stranded region and/or secondary structures, such asloops, e.g. a hairpin loop, or a triplex. The probes typically has alength of from about 8 to about 50, about 10 to about 40, such as about15 to about 30, preferably from about 18 to about 25, such as 19, 20,21, 22, 23 or 24 nucleotides. The probe may have an anchor sequencecapable of coupling to a membrane or an adaptor attached thereto. Forexample, the probe may be a guide polynucleotide/polynucleotide-guidedeffector protein complex, or a RecA coated probe. The probe may be aPNA, BNA, LNA, gamma PNA, triplex DNA or a morpholino probe. The probemay have a polynucleotide binding protein capable of moving along apolynucleotide attached thereto. The polynucleotide binding protein maybe bound to a leader sequence comprised in the adaptor.

In the method, the guide polynucleotide/polynucleotide-guided effectorprotein may be replaced by a protein that binds to a polynucleotidehaving a specific nucleotide sequence. Proteins that bind to apolynucleotide having a specific nucleotide sequence include, forexample, transcription activator-like effector nucleases and zinc fingernucleases. Such nucleases can be engineered to bind to particular siteswithin target polynucleotides.

In a particular embodiment, the method may be a method of detecting atarget polynucleotide comprising a double stranded polynucleotide in asample, the method comprising: (a) contacting the sample with a firstprobe and a second probe, wherein the first probe and the second probeform a complex with any target polynucleotide present in the sample, thefirst probe binds to a first sequence in the target double strandedpolynucleotide and comprises an anchor capable of coupling to amembrane, and the second probe binds to a second sequence in the targetdouble stranded polynucleotide and comprises an adaptor sequence; (b)contacting the sample with a transmembrane pore; (c) applying apotential to the transmembrane pore; and (d) monitoring for the presenceor absence of an effect resulting from the interaction of the complexwith the transmembrane pore to determine the presence or absence of thecomplex, thereby detecting the target double stranded polynucleotide inthe sample. Any unbound probes may be washed away prior to step (c).Step (d) typically comprises monitoring for the interaction of theadaptor with the transmembrane pore. The first sequence and secondsequence in the target polynucleotide are typically each a portion ofthe double stranded polynucleotide.

The second probe may further comprise a polynucleotide binding proteincapable of moving along a polynucleotide. The adaptor in the secondprobe may comprise a leader sequence and the polynucleotide bindingprotein may be bound to the leader sequence, and/or the adaptor maycomprise a barcode.

Step (a) of the method may comprise contacting the sample with two ormore first probes, wherein the two or more probes bind to differentsequences. Step (a) of the method may comprise contacting the sample andtransmembrane pore with two or more second probes. Typically, the two ormore second probes comprise different barcodes.

In methods using guide polynucleotides or probes binding to differentsequences, those sequences may be present in different targetpolynucleotides, within the same target polynucleotide or may bealternative sequences, such as SNPs, that may be present in the targetpolynucleotide.

In one embodiment, the method uses multiple pairs, such as from 2 to 50,3 to 40, 4 to 30, 5 to 25, 6 to 15 or 8 to 10 pairs, of first and secondprobes, wherein each pair binds to a different target polynucleotide. Inan alternate embodiment, the method may use a single first probe andmultiple second probes, which can be used to identify different oralternative sequences within a target polynucleotide.

The method may be used to detect one or more, such as 2, 3, 4, 5, 6, 78, 9, 10, 20, 30 or more, target polynucleotides in a complex backgroundfollowing enrichment of the target molecule. In one embodimentsequencing, e.g. nanopore sequencing, is used for the detection. Hencein this embodiment, the target DNA molecule may be identified primarilyby its sequence.

The method may be carried out as a multiplex assay. The multiplex assaymay utilize different barcodes. The barcodes may, for example, each havea distinct nucleotide sequence enabling the barcodes to be identified bya nanopore. In one embodiment a barcode sequence may be ligated to allpolynucleotides in a sample, prior to contacting the sample with theguide polynucleotide and polynucleotide-guided binding protein. A secondbarcode can be added to a second sample, prior to contacting the samplewith the guide polynucleotide and polynucleotide-guided binding protein.The first and second samples can be combined prior to or after additionof the guide polynucleotide and polynucleotide-guided binding protein,preferably after the guide polynucleotide and polynucleotide-guidedbinding protein have bound to the target polynucleotides. Where poolingof the samples occurs after the guide polynucleotide andpolynucleotide-guided binding protein have bound to the targetpolynucleotides, purification steps (including stress, removal ofnon-target bound protein, and/or removal of non-target polynucleotides)may be carried out prior to or after pooling. Multiple sample, such as2, 3, 4, 5, 6, 7 8, 9, 10, 20, 30 samples, can be labelled with barcodesand then combined in this way. In this embodiment all the samples can besequenced simultaneously, e.g. using the same flowcell, and identifiedusing their barcode adapter.

In another embodiment, barcodes and sequencing adapters may be addedafter the guide polynucleotide and polynucleotide-guided binding proteinhave bound to the target polynucleotides. For example, the barcodes andsequencing adaptors may be ligated on beads. The target-loaded,barcoded, adapted beads may be added to the sample after the guidepolynucleotide and polynucleotide-guided binding protein have bound tothe target polynucleotides and optionally after one or more purificationstaps (such as stress, removal of non-target bound protein, and/orremoval of non-target polynucleotides) have been carried out.

The method may comprise removing any polynucleotide-guided effectorprotein and/or guide polynucleotide, e.g. guidepolynucleotide/polynucleotide guided effector protein complex, that isnot specifically bound to the target polynucleotide. The excesspolynucleotide-guided effector protein and/or guide polynucleotide, e.g.guide polynucleotide/polynucleotide guided effector protein complex,present in the sample, which is not bound to target polynucleotide canproduce background when monitoring the interaction of the targetpolynucleotide/guide polynucleotide/polynucleotide guided effectorprotein complex with the pore. Guide polynucleotide,polynucleotide-guided effector protein and/or polynucleotide-guidedeffector protein/guide polynucleotide complex that is not specificallybound to the target polynucleotide may be separated from the complexcomprising the guide polynucleotide, polynucleotide-guided effectorprotein and target polynucleotide by binding the polynucleotides in thesample a surface, e.g. beads or a column. The target polynucleotides mayalso be separated from non-target polynucleotides in the sample bybinding the guide polynucleotide, polynucleotide-guided effector proteinand/or polynucleotide-guided effector protein/guide polynucleotidecomplex in the sample to a surface, e.g. beads or a column. The targetpolynucleotide(s) may, for example, be separated from the background bymeans of a ‘pulldown’ via a capture moiety on the guidepolynucleotide/polynucleotide-guided effector protein complex.

The method may comprise selectively denaturing any polynucleotide-guidedeffector protein that is not specifically bound to the targetpolynucleotide prior to step (b). ‘Off-target’ effects of guidepolynucleotide/polynucleotide-guided effector protein complex bindingmay be reduced by applying a thermal and/or chemical stress to the boundguide polynucleotide/polynucleotide-guided effector protein complex.Typically, in this embodiment, non-target bound polynucleotide-guidedeffector protein is selectively denatured by the heat stress or chemicalstress applied. The applied heat or chemical treatment can be selectedsuch that only free polynucleotide-guided effector protein (i.e.polynucleotide-guided effector protein that is not bound topolynucleotides in the sample, but which may be bound to guidepolynucleotide) and non-target bound polynucleotide-guided effectorprotein (i.e. polynucleotide-guided effector protein that is boundnon-specifically to polynucleotides in the sample, or “off target”polynucleotide-guided effector protein) is denatured. Target-boundpolynucleotide-guided effector protein remains bound to the targetpolynucleotide during the heat stress or chemical stress. Any off-targetpolynucleotide-guided effector protein is released from its non-specificbinding to the polynucleotides in the sample. In one embodiment, onlypolynucleotide-guided effector protein bound to a target sequence thatis exactly complementary to the corresponding sequence in the guidepolynucleotide remains bound to a polynucleotide during the stress.

Any suitable chemical stress can be used, such as urea (e.g. up to 6M,5M or 4M), guanidinium hydrochloride, extreme pH (acidic or alkaline,such as below pH6, pH5 or pH4 or above pH8, pH9 or pH10) or high saltconcentrations. Suitable conditions may readily be determined by theskilled person.

The chemical stress may be carried out for any time period that resultsin the selective disruption of non-specific binding ofpolynucleotide-guided effector protein to polynucleotides, withoutdisrupting specific binding of polynucleotide-guided effector protein totarget polynucleotide. The chemical stress may be carried out for fromabout 30 seconds to about 10 minutes, such as for about 1 minute, about2 minutes, about 3 minutes, about 5 minutes, about 6 minutes, about 7minutes, about 8 minutes or about 9 minutes.

The heat stress may be carried out at any suitable temperature.Typically the temperature is high enough to disrupt non-specific bindingof polynucleotide-guided effector protein to polynucleotides, but is lowenough that specific binding of polynucleotide-guided effector proteinto target polynucleotide is not disrupted. For example, the sample maybe heated to a temperature of from about 40° C. to about 65° C., about45° C. to about 65° C., about 50° C. to about 60° C., such as about 55°C.

The heat stress may be carried out for any time period that results inthe selective disruption of non-specific binding ofpolynucleotide-guided effector protein to polynucleotides, withoutdisrupting specific binding of polynucleotide-guided effector protein totarget polynucleotide. The heat stress may be carried out for from about30 seconds to about 10 minutes, such as for about 1 minute, about 2minutes, about 3 minutes, about 5 minutes, about 6 minutes, about 7minutes, about 8 minutes or about 9 minutes.

A purification step may be used to remove excess, unboundpolynucleotide-guided effector protein and/or guide polynucleotide. Thismay be achieved, for example, by adding polyethylene glycol (PEG) andsodium chloride to the sample and contacting the sample withparamagnetic beads coated with carboxyl groups such that thepolynucleotides present in the sample bind to the beads. Suitable beadsinclude commercially available SPRI beads and standard protocols knownin the art may be used. In one embodiment, the targetpolynucleotide/guide polynucleotide/polynucleotide-guided effectorprotein complex may subsequently be separated from non-targetpolynucleotides using a surface, e.g. a different capture bead.Typically, here the guide polynucleotide/polynucleotide-guided effectorprotein may contain a binding moiety that is used to specifically bindthe target polynucleotide/guide polynucleotide/polynucleotide-guidedeffector protein complex to the surface. Any non-bound polynucleotidesmay be washed away. The target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complex may beeluted from the surface by any suitable means, or the surface may beused to deliver the complex to a pore, e.g. where the surface is beads.

‘Off-target’ effects may be minimised further by purification the targetpolynucleotide/guide polynucleotide/polynucleotide-guided effectorprotein complexes on a capture surface using a first binding moiety onthe guide polynucleotide/polynucleotide-guided effector protein, e.g. onthe guide polynucleotide, eluting the target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complexes andtransferring the target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complexes to asecond specific capture surface using a second binding moiety on theguide polynucleotide/polynucleotide-guided effector protein, e.g. on theguide polynucleotide. This can be achieved, for example, where the firstbinding moiety and the second binding moiety are both end extensions, orother single stranded polynucleotide sequences capable of binding to anoligonucleotide, on the guide polynucleotide. The first end extension onthe guide polynucleotide has a sequence complementary to a first captureoligonucleotide on a first capture surface, e.g. a bead, and the secondend extension on the guide polynucleotide has a sequence complementaryto a second capture oligonucleotide on a second capture surface, e.g. abead. One way of configuring this is depicted in FIG. 44. In FIG. 44,the crRNA comprises a 3′ DNA extension used for capture of the targetmolecule on a bead, column or surface (sequence d of FIG. 44) and thetracrRNA comprises a 5′ DNA extension (sequence a−c of FIG. 44). Therelease of the target from the first capture surface, e.g. a bead, maybe effected by the phenomenon known as toehold displacement.

The target polynucleotide/guide polynucleotide/polynucleotide-guidedeffector protein complex is first separated from non-targetpolynucleotides by capture on beads bearing a first captureoligonucleotide complementary to the first end extension. Non-targetpolynucleotides are washed away. The target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complex may beeluted from the bead by toehold displacement, via the addition of acompetitor oligonucleotide that competes for the binding to the beadwith the first end extension on the guide polynucleotide. In thisembodiment, the first capture oligonucleotide is longer than the firstend extension and comprises a first sequence and a second sequence,wherein the first sequence is complementary to a sequence in the firstend extension and the first and second sequences are both complementaryto the sequence of the competitor oligonucleotide. Typically the firstsequence has a length of from 5 to 40, such as 10 to 30 or 15 to 25nucleotides, for example 20 nucleotides and the second sequence has alength of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides. The competitor oligonucleotide may have a lengthof from 10 to 80, such as 20 to 60 or 30 to 50 nucleotides, for example40 nucleotides. The first capture oligonucleotide may have a length offrom 10 to 80, such as 20 to 60 or 30 to 50 nucleotides, for example 40nucleotides. The capture oligonucleotide may have the same length as thecompetitor oligonucleotide, or the capture oligonucleotide may be longeror shorter than the competitor oligonucleotide, provided that captureoligonucleotide and competitor oligonucleotide have sequences that arecomplementary over both the first and second sequences. In thisembodiment, the first end extension comprises an end portion, which isat the 5′ end in a 5′ end extension or at the 3′ end in a 3′ endextension, which has a sequence that is not complementary to a sequencein the first capture oligonucleotide, and a portion that has a sequencethat is complementary to the first sequence in the first captureoligonucleotide. The end portion of the first end extension maytypically have a length of from 2 to 10 nucleotides, such as 3, 4, 5 or6 nucleotides. The portion of the first end extension that iscomplementary to the first capture oligonucleotide may typically have alength of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides.

Following elution of the target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complex, thecomplex is bound to a second ‘delivery’ bead via second end extension onthe guide polynucleotide. The second ‘delivery’ bead comprises a secondcapture oligonucleotide that is complementary to the second endextension. The second capture oligonucleotide may have a length of from5 to 40, such as 10 to 30 or 15 to 25 nucleotides, for example 20nucleotides or a length of from 10 to 80, such as 20 to 60 or 30 to 50nucleotides, for example 40 nucleotides. The second end extension mayhave a length of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides,for example 20 nucleotides. The second capture oligonucleotide may havethe same length as the second end extension, or the second captureoligonucleotide may be longer or shorter than the end extension,provided that second capture oligonucleotide and second end extensionhave sequences that are complementary over a length of from 5 to 40,such as 10 to 30 or 15 to 25 nucleotides, for example 20 nucleotides.The second end extension has a sequence that does hybridise to the firstcapture nucleotide, the first end extension or the competitoroligonucleotide. The second capture oligonucleotide also has a sequencethat does hybridise to the first capture nucleotide, the first endextension or the competitor oligonucleotide.

Accordingly, where the guide polynucleotide comprises a first endextension and a second end extension, and the method may comprise priorto step (b):

(i) contacting the sample with a surface having bound thereto a firstcapture oligonucleotide comprising a sequence complementary to the firstend extension, such that the guide polynucleotide/polynucleotide-guidedeffector protein/target polynucleotide complex is bound to the surface;

(ii) contacting the guide polynucleotide/polynucleotide-guided effectorprotein/target polynucleotide complex bound to the surface with acompetitor oligonucleotide, such that the guidepolynucleotide/polynucleotide-guided effector protein/targetpolynucleotide complex is released from the surface;

(iii) contacting the guide polynucleotide/polynucleotide-guided effectorprotein/target polynucleotide complex with beads having bound thereto asecond capture oligonucleotide comprising a sequence complementary tothe second end extension, such that the guidepolynucleotide/polynucleotide-guided effector protein/targetpolynucleotide complex is bound to the beads; and optionally

(iv) delivering the beads to the transmembrane pore.

In different embodiments of the invention, there may be: (i) no heat orchemical stress, purification to remove excess, unbound and/ornon-target bound polynucleotide-guided effector protein or toeholdpurification; (ii) only heat or chemical stress; (iii) only purificationto remove excess, unbound and/or non-target-bound polynucleotide-guidedeffector protein; (iv) only toehold purification; (v) heat or chemicalstress and purification to remove excess, unbound and/ornon-target-bound polynucleotide-guided effector protein; (vi) heat orchemical stress and toehold purification; (vii) purification to removeexcess, unbound and/or non-target-bound polynucleotide-guided effectorprotein and toehold purification; or (viii) heat or chemical stress,purification to remove excess, unbound and/or non-target-boundpolynucleotide-guided effector protein and toehold purification.

The beads to which the target polynucleotide/guidepolynucleotide/polynucleotide-guided effector protein complex is boundmay be used to deliver the complex to a pore. For example, the beads maybe magnetic and the target polynucleotide bound to the beads may bedrawn into the wells of a flowcell comprising the pore by theapplication of a magnetic field placed underneath the flowcell, or canbe allowed to settle by gravity. Sequencing can be initiated by flowingtether, such as an oligonucleotide-cholesterol tether which hybridizesto the adaptor ends, over the beads, which tethers the beads to themembrane. Alternatively, the tether can be introduced into the membranebefore the bead-target polynucleotide conjugate is added. For example,an oligonucleotide-cholesterol tether which hybridizes to the adaptorends may be integrated into the membrane in the flowcell by flowingrunning buffer and the tether through the flowcell before thebeads-target polynucleotide(s) are added. In this situation, when thebeads-target polynucleotide(s) are added to the flowcell, they becometethered to the membrane when they encounter the oligonucleotide that isanchored in the membrane by the cholesterol.

In some embodiments, the target polynucleotides may be adapted fornanopore sequencing. For example, all of the polynucleotides in thesample may have sequencing adaptors added to one or both ends prior tostep (a) of the method. The polynucleotides in the sample may befragmented prior to addition of the sequencing adaptors. Alternatively,the target polynucleotides may have sequencing adaptors added to one orboth ends after step (a). In this embodiment, the sequencing adaptorsmay be added before or after separation of the target from non-targetpolynucleotides. The sequencing adaptor typically comprises apolynucleotide binding protein that is capable of moving along thepolynucleotide. When the sequencing adaptor is added after step (a) thepolynucleotide-guided effector protein/guide polynucleotide complexremains bound to the target polynucleotide. After binding of theadaptor, in some embodiments, generally where the target polynucleotidehas been separated from non-target polynucleotides prior to adaptoraddition, the polynucleotide-guided effector protein/guidepolynucleotide complex may be displaced by the polynucleotide bindingprotein that is capable of moving along the polynucleotide loaded on theadaptor. Displacement of the polynucleotide-guided effectorprotein/guide polynucleotide complex by the polynucleotide bindingprotein that is capable of moving along the polynucleotide can becontrolled by the addition of one or more cofactor needed for thepolynucleotide binding protein to moving along a polynucleotide.

The target polynucleotide may be adapted for nanopore sequencing byligation of adaptors to either or both of its free ends whilst bound tothe surface, e.g. column or beads, via the guidepolynucleotide/polynucleotide-guided effector protein. The ends may bedA-tailed to facilitate adaptor binding.

Target Polynucleotide

The polynucleotide can be a nucleic acid, such as deoxyribonucleic acid(DNA) or ribonucleic acid (RNA). The polynucleotide can comprise onestrand of RNA hybridised to one strand of DNA. The polynucleotide may beany synthetic nucleic acid known in the art, such as peptide nucleicacid (PNA), glycerol nucleic acid (GNA), threose nucleic acid (TNA),locked nucleic acid (LNA) or other synthetic polymers with nucleotideside chains. The PNA backbone is composed of repeatingN-(2-aminoethyl)-glycine units linked by peptide bonds. The GNA backboneis composed of repeating glycol units linked by phosphodiester bonds.The TNA backbone is composed of repeating threose sugars linked togetherby phosphodiester bonds. LNA is formed from ribonucleotides as discussedabove having an extra bridge connecting the 2′ oxygen and 4′ carbon inthe ribose moiety.

The polynucleotide is preferably DNA, RNA or a DNA or RNA hybrid, mostpreferably DNA. The target polynucleotide comprises a double strandedregion to which the guide-polynucleotide and polynucleotide-guidedeffector protein bind. The target polypeptide may be double stranded.The target polypeptide may comprise single stranded regions and regionswith other structures, such as hairpin loops, triplexes and/orquadruplexes. The DNA/RNA hybrid may comprise DNA and RNA on the samestrand. Preferably, the DNA/RNA hybrid comprises one DNA strandhybridized to a RNA strand.

The target polynucleotide can be any length. For example, thepolynucleotides can be at least 10, at least 50, at least 100, at least150, at least 200, at least 250, at least 300, at least 400 or at least500 nucleotides or nucleotide pairs in length. The target polynucleotidecan be 1000 or more nucleotides or nucleotide pairs, 5000 or morenucleotides or nucleotide pairs in length or 100000 or more nucleotidesor nucleotide pairs in length. The target polynucleotide may be anoligonucleotide. Oligonucleotides are short nucleotide polymers whichtypically have 50 or fewer nucleotides, such 40 or fewer, 30 or fewer,20 or fewer, 10 or fewer or 5 or fewer nucleotides. The targetoligonucleotide is preferably from about 15 to about 30 nucleotides inlength, such as from about 20 to about 25 nucleotides in length. Forexample, the oligonucleotide can be about 15, about 16, about 17, about18, about 19, about 20, about 21, about 22, about 23, about 24, about25, about 26, about 27, about 28, about 29 or about 30 nucleotides inlength.

The target polynucleotide may be a polynucleotide associated with adisease and/or a microorganism.

The method may detect multiple, such as from 2 to 50, 3 to 40, 4 to 30,5 to 25, 6 to 15 or 8 to 10, target polynucleotides. The targetpolynucleotides may be a group of polynucleotides. For instance, thegroup may be associated with a particular phenotype. The group may beassociated with a particular type of cell. For instance, the group maybe indicative of a bacterial cell. The group may be indicative of avirus, a fungus, a bacterium, a mycobacterium or a parasite.

The target polynucleotides may be a group of two or more polynucleotidesthat are, or comprise, biomarkers associated with a particular diseaseor condition. The biomarkers can be used to diagnose or prognose thedisease or condition. Suitable panels of biomarkers are known in theart, for example as described in Edwards, A. V. G. et al. (2008)Mol.Cell. Proteomics 7, p 1824-1837; Jacquet, S. et al. (2009), Mol. Cell.Proteomics 8, p 2687-2699; Anderson N. L. et al (2010) Clin. Chem. 56,177-185. The disease or condition is preferably cancer, heart disease,including coronary heart disease and cardiovascular disease, or aninfectious disease, such as tuberculosis or sepsis.

The target oligonucleotide or polynucleotide is preferably a microRNA(or miRNA) or a small interfereing RNA (siRNA). The group of two or moretarget polynucleotides may be a group of two or more miRNAs. SuitablemiRNAs for use in the invention are well known in the art. For instance,suitable miRNAs are stored on publically available databases (Jiang Q.,Wang Y., Hao Y., Juan L., Teng M., Zhang X., Li M., Wang G., Liu Y.,(2009) miR2Disease: a manually curated database for microRNAderegulation in human disease. Nucleic Acids Res.).

Polynucleotide Guided Effector Protein

The polynucleotide-guided effector protein may be any protein that bindsto a guide-polynucleotide and which binds to the polynucleotide to whichthe guide polynucleotide binds. The polynucleotide-guided effectorprotein may; by way of non-limiting example, comprise a targetpolynucleotide recognition domain and at least one nuclease domain. Therecognition domain binds a guide polynucleotide (e.g. RNA) and a targetpolynucleotide DNA). The polynucleotide-guided effector protein maycontain one nuclease domain that cuts one or both strands of a doublestranded polynucleotide, or may contain two nuclease domains wherein afirst nuclease domain is positioned for cleavage of one strand of thetarget polynucleotide and a second nuclease domains is positioned forcleavage of the complementary strand of the target polynucleotide. Thenuclease domains may be active or inactive. For example, the nucleasedomain or one or both of the two nuclease domains may be inactivated bymutation.

The guide polynucleotide may be a guide RNA, a guide DNA, or a guidecontaining both DNA and RNA. The guide polynucleotide is preferably aguide RNA. Therefore the polynucleotide-guided effector protein ispreferably a RNA-guided effector protein.

The RNA-guided effector protein may be any protein that binds to theguide-RNA. The RNA-guided effector protein typically binds to a regionof guide RNA that is not the region of guide RNA which binds to thetarget polynucleotide. For example, where the guide RNA comprises crRNAand tracrRNA, the RNA-guided effector protein typically binds to thetracrRNA and the crRNA typically binds to the target polynucleotide. TheRNA-guided effector protein preferably also binds to a targetpolynucleotide. The region of the guide RNA that binds to the targetpolynucleotide may also bind to the RNA-guided effector protein. TheRNA-guided effector protein typically binds to a double stranded regionof the target polynucleotide. The region of the target polynucleotide towhich the RNA-guided effector protein binds is typically located closeto the sequence to which the guide RNA hybridizes. The guide RNA andRNA-guided effector protein typically form a complex, which complex thenbinds to the target polynucleotide at a site determined by the sequenceof the guide RNA.

The RNA-guided effector protein may bind upstream or downstream of thesequence to which the guide RNA binds. For example, the RNA-guidedeffector protein may bind to a protospacer adjacent motif (PAM) in DNAlocated next to the sequence to which the guide RNA binds. A PAM is ashort (less than 10, typically a 2 to 6 base pair) sequence, such as5′-NGG-3′ (wherein N is any base), 5′-NGA-3′, 5′-YG-3′ (wherein Y is apyrimidine), 5′ TTN-3′ or 5′-YTN-3′. Different RNA-guided effectorproteins bind to different PAMs. RNA-guided effector proteins may bindto a target polynucleotide which does not comprise a PAM, in particular,where the target is RNA or a DNA/RNA hybrid.

The RNA-guided effector protein is typically a nuclease, such as aRNA-guided endonuclease. The RNA-guided effector protein is typically aCas protein. The RNA-guided effector protein may be Cas, Csn2, Cpf1,Csf1, Cmr5, Csm2, Csy1, Cse1 or C2c2. The Cas protein may Cas3, Cas 4,Cas8a, Cas8b, Cas8c, Cas9, Cas10 or Cas10d. Preferably, the Cas proteinis Cas9. Cas, Csn2, Cpf1, Csf1, Cmr5, Csm2, Csy1 or Cse1 is preferablyused where the target polynucleotide comprises a double stranded DNAregion. C2c2 is preferably used where the target polynucleotidecomprises a double stranded RNA region.

A DNA-guided effector protein, such as proteins from the RecA family maybe used to target DNA. Examples of proteins from the RecA family thatmay be used are RecA, RadA and Rad51. The nuclease activity of theRNA-guided endonuclease may be disabled. One or more of the catalyticnuclease sites of the RNA-guided endonuclease may be inactivated. Forexample, where the RNA-guided endonuclease comprises two catalyticnuclease sites, one or both of the catalytic sites may be inactivated.Typically one of the catalytic sites will cut one strand of thepolynucleotide to which it specifically binds and the other catalyticsite will cut the opposite strand of the polynucleotide. Therefore, theRNA-guided endonuclease may cut both strands, one strand or neitherstrand of a double stranded region of a target polynucleotide.

The polynucleotide-guided effector protein y, by way of non-limitingexample, be Cas9. Cas9 has a bi-lobed; multi-domain protein structurecomprising target recognition and nuclease lobes. The recognition lobebinds guide RNA and DNA. The nuclease lobe contains the HNH and RuvCnuclease domains which are positioned for cleavage of the complementaryand non-complementary strands of the target DNA. The structure of Cas 9is detailed in Nishimasu, H., et al., (2014) Crystal Structure of Cas9in Complex with Guide RNA and Target DNA. Cell 156, 935-949. Therelevant PDB reference for Cas9 is 5F9R (Crystal structure ofcatalytically-active Streptococcus pyogenes CRISPR-Cas9 in complex withsingle-guided RNA and double-stranded DNA primed for target DNAcleavage).

The Cas9 may be an ‘enhanced specificity’ Cas9 that shows reducedoff-target binding compared to wild-type Cas9. An example of such an‘enhanced specificity’ Cas9 is S. pyogenes Cas9D10A/H840A/K848A/K1003A/R1060A. ONLP12296 is the amino acid sequence ofS. pyogenes Cas9 D10A/H840A/K848A/K1003A/R1060A having a C-terminalTwin-Strep-tag with TEV-cleavable linker.

Catalytic sites of a RNA-guided endonuclease may be inactivated bymutation. The mutation may be a substitution, insertion or deletionmutation. For example, one or more, such as 2, 3, 4, 5, or 6 amino acidsmay be substituted or inserted into or deleted from the catalytic site.The mutation is preferably a substitution insertion, more preferablysubstitution if a single amino acid at the catalytic site. The skilledperson will be readily able to identify the catalytic sites of aRNA-guided endonuclease and mutations that inactivate them. For example,where the RNA-guided endonuclease is Cas9, one catalytic site may beinactivated by a mutation at D10 and the other by a mutation at H640.

An inactivated (‘dead’) polynucleotide-guided effector protein that doesnot cut the target polynucleotide and so shows no directionality bias.An active (‘live’) polynucleotide-guided effector protein that cuts thetarget polynucleotide may remain bound to just one of the two ends ofthe cut site and so may show some directionality bias.

The polynucleotide-guided effector protein typically remains bound tothe target polynucleotide for a prolonged period. Thepolynucleotide-guided effector protein preferably remains bound to thetarget polynucleotide for from at least about 1 to at least about 10,such as about 2 to about 8 hours or about 4 to about 6 hours in theabsence of a transmembrane pore and a transmembrane potential. Thepolynucleotide-guided effector protein may be displaced from the targetpolynucleotide by the interaction with a transmembrane pore under anapplied potential.

In one embodiment, the polynucleotide-guided effector protein may holdthe target polypeptide in the transmembrane pore for a short periodwhilst it is being displaced. This results in a detectable signal, thatmay be seen as a stutter in a trace of the current passing through thepore, but can also be detected by other means, for example by opticalmeasurements or tunneling.

The polynucleotide-guided effector protein may have the ability to movealong and slow the polynucleotide. For example, the RNA-guided effectorprotein may act as a sliding molecular brake. In this embodiment, theRNA-guided effector protein may be used as a motor protein to controlthe movement of the target polynucleotide, or the guide RNA, through thetransmembrane pore.

Guide Polynucleotide

The guide polynucleotide comprises a sequence that is capable ofhybridising to a target polynucleotide and is also capable of binding toa polynucleotide-guided effector protein. The guide polynucleotide mayhave any structure that enables it to bind to the target polynucleotideand to a polynucleotide-guided effector protein.

The guide polynucleotide typically hybridizes to a sequence of about 20nucleotides in the target polynucleotide. The sequence to which theguide RNA binds may be from about 10 to about 40, such as about 15 toabout 30, preferably from about 18 to about 25, such as 19, 20, 21, 22,23 or 24 nucleotides. The guide polynucleotide is typicallycomplementary to one strand of a double stranded region of the targetpolynucleotide. The guide polynucleotide comprises a nucleotide sequenceof from about 10 to about 40, such as about 15 to about 30, preferablyfrom about 18 to about 25, such as 19, 20, 21, 22, 23 or 24, nucleotidesthat is complementary to the sequence of, or to a sequence in, thetarget polynucleotide. The degree of complementarity is preferablyexact.

The guide RNA may be complementary to a region in the targetpolynucleotide that is 5′ to a PAM. This is preferred where the targetpolynucleotide comprises DNA, particularly where the RNA effectorprotein is Cas9 or Cpf1. The guide RNA may be complementary to a regionin the target polynucleotide that is flanked by a guanine. This ispreferred where the target polynucleotide comprises RNA, particularlywhere the RNA effector protein is C2c2.

The guide RNA may have any structure that enables it to bind to thetarget polynucleotide and to a RNA-guided effector protein. The guideRNA may comprise a crRNA that binds to a sequence in the targetpolynucleotide and a tracrRNA. The tracrRNA typically binds to theRNA-guided effector protein. Typical structures of guide RNAs are knownin the art. For example, the crRNA is typically a single stranded RNAand the tracrRNA typically has a double stranded region of which onestrand is attached to the 3′ end of the crRNA and a part that forms ahairpin loop at the 3′ end of the strand that is not attached to thecrRNA. The crRNA and tracrRNA may be transcribed in vitro as a singlepiece sgRNA.

The guide RNA may comprise other components, such as additional RNAbases or DNA bases or other nucleobases. The RNA and DNA bases in theguide RNA may be natural bases or modified bases. A guide DNA may beused in place of a guide RNA, and a DNA-guided effector protein usedinstead of a RNA-guided effector protein. The used of a guide DNA and aDNA-guided effector protein may be preferred where the targetpolynucleotide is RNA.

The guide polynucleotide may be specifically modified for use in amethod of the invention. The invention provides a guide polynucleotide,particularly a guide RNA, that comprises (i) an adaptor sequence,optionally including a leader sequence or (ii) an anchor capable ofcoupling to a membrane.

The guide polynucleotide of the invention may be any of the guidepolynucleotides discussed herein to which (i) an adaptor and/or (ii) ananchor capable of coupling to a membrane is attached.

The (i) the anchor or (ii) the adaptor may be present at the 5′ end ofthe tracrRNA, the 3′ end of the tracrRNA, the 3′ end of the crRNA, orinternally, for example, wherein the tracrRNA and crRNA are comprised ina sgRNA. See FIGS. 2-4 and 25, for examples. The (i) the anchor or (ii)the adaptor may be added to the 5′ end of the crRNA, e.g. via a chemicalgroup or spacer. The (i) the anchor or (ii) the adaptor may be added tothe guide polynucleotide via a chemical group or spacer. The (i) theanchor or (ii) the adaptor may be attached to the 5′ or 3′ end of theguide polynucleotide, such as to the 5′ or 3′ end of a tracrRNA or the5′ or 3′ end of a crRNA by any suitable means, e.g. ligation, via achemical group, e.g. thiols, click groups, biotin etc., or via a DNA,RNA, PNA, BNA, LNA, TNA spacer. Where the spacer is a polynucleotide,the spacer may have a length of from 1 to 30, such as from 2 to 20, 3 to15, 4 to 10, such as 5, 6, 7 8 or 9, nucleotides.

The anchor may be attached to an oligonucleotide (anchoroligonucleotide) that is complementary to an end extension, or aninternal loop sequence, in the guide polynucleotide. The 5′ end of thetracrRNA, the 3′ end of the tracrRNA, the 3′ end of the crRNA or the 5′end of the crRNA may have an end extension having a length of, forexample, from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides. The anchor oligonucleotide may have the samelength as the end extension, or the anchor oligonucleotide may be longeror shorter than the end extension, provided that anchor oligonucleotideand end extension have sequences that are complementary over a length offrom 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, for example 20nucleotides. The anchor oligonucleotide may have a length of, forexample, from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides. The internal loop sequence may have any of thelengths specified above.

The guide polynucleotide may be synthetically modified. Both the 5′ and3′ ends of crRNA and tracrRNA can be modified. See Lee et al., (2017)Synthetically modified guide RNA and donor DNA are a versatile platformfor CRISPR-Cas9 engineering. eLIFE; 6:e25312, incorporated by referenceherein. Synthetic modification may comprise incorporation of modified orartificial bases into guide RNA (or guide DNA), including DNA, RNA, PNA,LNA, BNA, DNA spacers, RNA spacers and abasic spacers e.g., Sp18.Alternatively modification may comprise modification with chemicalmoieties that are structurally unrelated to nucleotide bases such asplanar hydrophobic molecules, chemical tags, fluorescent molecules,aptamer sequences, amines, azides, alkynes, thiols, click groups,biotins.

The guide polynucleotide of the invention may have a polynucleotidebinding protein capable of moving along a polynucleotide attachedthereto. The polynucleotide binding protein may be bound close to oneend of a strand of the guide RNA, typically close to the 5′ end. The endto which the polynucleotide binding protein is bound is typicallymodified by the addition of an adaptor, preferably an adaptor comprisinga leader sequence. Where the guide RNA comprises a leader sequence thepolynucleotide binding protein is typically bound to the leadersequence.

Where the guide RNA comprises a crRNA, the polynucleotide bindingprotein may be positioned such that it is capable of moving along thecrRNA. Such a guide RNA is useful in a method in which the crRNAtranslocates through the transmembrane pore in order to detect thepresence or absence of the complex.

The guide polynucleotide may be specifically adapted to enable captureof the target polynucleotide on a surface, such as a bead or column.This allows target polynucleotides to which a guidepolynucleotide/polynucleotide-guided effector protein complex is boundto be captured and separated from non-target polynucleotides in asample, which can then be washed away. The guide polynucleotide maycomprise an end extension at the 3′ or 5′ end, which has a sequence thatis complementary to the sequence of a capture oligonucleotide that isbound to a surface, such as to a bead or column. For example, thecapture oligonucleotide may be bound to the surface by an affinity tag.Any suitable affinity tag may be used. One example is abiotin-streptavidin affinity tag. The capture oligonucleotide may have alength of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides or a length of from 10 to 80, such as 20 to 60 or30 to 50 nucleotides, for example 40 nucleotides. The end extension mayhave a length of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides,for example 20 nucleotides. The capture oligonucleotide may have thesame length as the end extension, or the capture oligonucleotide may belonger or shorter than the end extension, provided that captureoligonucleotide and end extension have sequences that are complementaryover a length of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides,for example 20 nucleotides.

The guide polynucleotide may comprise a first binding moiety and asecond binding moiety. The first binding moiety and the second bindingmoiety may both be end extensions, or other single strandedpolynucleotide sequences capable of binding to an oligonucleotide, onthe guide polynucleotide. The first end extension on the guidepolynucleotide may have a sequence complementary to a first captureoligonucleotide on a first capture surface, e.g. a bead, and the secondend extension on the guide polynucleotide may have a sequencecomplementary to a second capture oligonucleotide on a second capturesurface, e.g. a bead. One way of configuring this is depicted in FIG.44. In FIG. 44, the crRNA comprises a 3′ DNA extension used for captureof the target molecule on a bead, column or surface (sequence d of FIG.44) and the tracrRNA comprises a 5′ DNA extension (sequence a−c of FIG.44). In one embodiment, the first end extension comprises an endportion, which is at the 5′ end in a 5′ end extension or at the 3′ endin a 3′ end extension, which has a sequence that is not complementary toa sequence in the first capture oligonucleotide, and a portion that hasa sequence that is complementary to the first sequence in the firstcapture oligonucleotide. The end portion of the first end extension maytypically have a length of from 2 to 10 nucleotides, such as 3, 4, 5 or6 nucleotides. The portion of the first end extension that iscomplementary to the first capture oligonucleotide may typically have alength of from 5 to 40, such as 10 to 30 or 15 to 25 nucleotides, forexample 20 nucleotides.

The second end extension has a sequence that does hybridise to the firstcapture nucleotide, the first end extension or the competitoroligonucleotide. The second capture oligonucleotide also has a sequencethat does hybridise to the first capture nucleotide, the first endextension or the competitor oligonucleotide. The end extension may beattached to the 5′ or 3′ end of the guide polynucleotide, such as to the5′ or 3′ end of a tracrRNA or the 5′ or 3′ end of a crRNA. The endextension may be attached to the guide polynucleotide by any suitablemeans. The end extension may, for example, be may be added via achemical group or spacer, e.g. ligation, via a chemical group, e.g.thiols, click groups, biotin etc., or via a DNA, RNA, PNA, BNA, LNA, TNAspacer. Where the spacer is a polynucleotide, the spacer may have alength of from 1 to 30, such as from 2 to 20, 3 to 15, 4 to 10, such as5, 6, 7 8 or 9, nucleotides. The end extension may be present at the 5′end of the tracrRNA, the 3′ end of the tracrRNA, the 3′ end of thecrRNA, the 5′ end of the crRNA or may be substituted by a sequence addedinternally to the guide RNA, for example, wherein the tracrRNA and crRNAare comprised in a sgRNA. See FIGS. 41 and 44 for examples. Where aninternal sequence is used to perform the function described herein forthe end extension, it is typically present in a loop structure withinthe guide polynucleotide, or is otherwise accessible for hybridizationto the capture oligonucleotide.

The present invention also provides a guide polynucleotide of theinvention bound to a polynucleotide-guided effector protein as definedherein.

Also provided by the invention are a panel of guide polynucleotides,preferably guide RNAs of the invention, and a panel of guidepolynucleotide/polynucleotide-guided effector protein complexes,preferably guide RNA/RNA-guided effector protein complexes, of theinvention. The panel of guide polynucleotides or guidepolynucleotide/polynucleotide-guided effector protein complexes may becomprised in a kit.

A panel of the invention may comprise guide polynucleotides of theinvention and a panel of guide polynucleotides and polynucleotide-guidedeffector proteins that may be used together in a method of theinvention. The guide polynucleotides and polynucleotide-guided effectorproteins may be present in guide polynucleotide/polynucleotide-guidedeffector protein complexes.

A panel may comprise a first guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex thatcomprises an anchor capable of coupling to a membrane and a second guidepolynucleotide or guide polynucleotide/polynucleotide-guided effectorprotein complex that comprises an adaptor, wherein the first guidepolynucleotide or guide polynucleotide/polynucleotide-guided effectorprotein complex and the second guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex bind todifferent sequences in the same target polynucleotide. The panel maycomprise multiple, such as from 2 to 50, 3 to 40, 4 to 30, 5 to 25, 6 to15 or 8 to 10, such first and second guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complexes. Wherethe panel comprises multiple first and second guide polynucleotides orguide polynucleotide/polynucleotide-guided effector protein complexes,each second guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex typicallycomprises a different adaptor. This enables the panel to distinguishbetween different target polynucleotides present in the sample.

A panel may comprise a first guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex that bindsto a first sequence of the target polynucleotide and a second guidepolynucleotide or guide polynucleotide/polynucleotide-guided effectorprotein complex that binds to a second sequence of the targetpolynucleotide. Further guide polynucleotides or guidepolynucleotide/polynucleotide-guided effector protein complexes bindingto further sequences of the same target polynucleotide may be includedin the panel. The first, second and further guide polynucleotides orguide polynucleotide/polynucleotide-guided effector protein complexesmay comprise the same or different adaptors, or may comprise noadaptors. The first guide polynucleotides or guidepolynucleotide/polynucleotide-guided effector protein complexes maycomprise a membrane anchor and the second and/or further guidepolynucleotides or guide polynucleotide/polynucleotide-guided effectorprotein complexes may comprise the same adaptors or, preferably,different adaptors.

No adaptors need to be included in the guide polynucleotides or guidepolynucleotide/polynucleotide-guided effector protein complexes wherethe panel is for use in a method that detects the effect of the guidepolynucleotide/polynucleotide-guided effector protein complex bound tothe target polynucleotide interacting with the transmembrane pore bydetecting a signal, e.g. change current passing through the pore, causedby the guide polynucleotide/polynucleotide-guided effector proteincomplex stalling passage of the target polynucleotide through the poreor by the bound guide polynucleotide/polynucleotide-guided effectorprotein complex passing through the pore.

The first, second and/or further guide polynucleotides or guidepolynucleotide/polynucleotide-guided effector protein complexes may bindto the same part of the target polynucleotide, but may each be specificfor a different polymorphism present in that part of the targetpolynucleotide. In this embodiment, each guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex that isspecific for a different polymorphism may comprise a different adaptorand/or leader sequence. The method of the invention can distinguishbetween different adaptors and/or between different leader sequences,and hence can be used to identify a polymorphism.

A panel may comprise a first guide polynucleotide or guidepolynucleotide/polynucleotide-guided effector protein complex that bindsto a first target polynucleotide and a second guide polynucleotide orguide polynucleotide/polynucleotide-guided effector protein complex thatbinds to a second target polynucleotide. Further guide polynucleotidesor guide polynucleotide/polynucleotide-guided effector protein complexesbinding to further target polynucleotides may be included in the panel.For example, the first, second and/or further guide polynucleotides orguide polynucleotide/polynucleotide-guided effector proteins may each becoupled to an anchor and/or other binding moieties. Such a panel wouldbe useful for delivering multiple polynucleotides of interest in asample to a transmembrane pore for further characterization, for exampleby sequencing. For example, such a panel would select for multiplepolynucleotides of interest and tether them to the membrane comprising atransmembrane pore so that other polynucleotides in the sample may bewashed away prior to the application of a membrane potential.

Sample

The sample may be any suitable sample. The sample is typically one thatis known to contain or is suspected of containing at least one of thetarget polynucleotides. The method can be used to select targetpolynucleotides for delivery to the transmembrane pore. Other componentsof the sample may be washed away, for example, they may be flushed outof a cell comprising the transmembrane pore. Such other componentsinclude one or more of the following: proteins, which may be folded orunfolded, peptides, carbohydrates, polymers, such as non-targetpolynucleotides, and cell debris.

The sample may be a biological sample. The invention may be carried outin vitro on a sample obtained from or extracted from any organism ormicroorganism. The organism or microorganism is typically archaean,prokaryotic or eukaryotic and typically belongs to one the fivekingdoms: plantae, animalia, fungi, monera and protista. The inventionmay be carried out in vitro on a sample obtained from or extracted fromany virus.

The sample is preferably a fluid sample. The sample typically comprisesa body fluid. The body fluid may be obtained from a human or animal. Thehuman or animal may have, be suspected of having or be at risk of adisease. The sample may be urine, lymph, saliva, mucus, seminal fluid oramniotic fluid, but is preferably whole blood, plasma or serum.Typically, the sample is human in origin, but alternatively it may befrom another mammal such as from commercially farmed animals such ashorses, cattle, sheep or pigs or may alternatively be pets such as catsor dogs.

Alternatively a sample of plant origin is typically obtained from acommercial crop, such as a cereal, legume, fruit or vegetable, forexample wheat, barley, oats, canola, maize, soya, rice, bananas, apples,tomatoes, potatoes, grapes, tobacco, beans, lentils, sugar cane, cocoa,cotton, tea or coffee.

The sample may be a non-biological sample. The non-biological sample ispreferably a fluid sample. Examples of non-biological samples includesurgical fluids, water such as drinking water, sea water or river water,and reagents for laboratory tests.

The sample may be processed prior to being assayed, for example bycentrifugation or by passage through a membrane that filters outunwanted molecules or cells, such as red blood cells. The sample may bemeasured immediately upon being taken. The sample may also be typicallystored prior to assay, preferably below −70° C.

The sample may comprise genomic DNA. The genomic DNA may be fragmentedor step (a) of the method may further comprise fragmenting the genomicDNA. The DNA may be fragmented by any suitable method. For example,methods of fragmenting DNA are known in the art. Such methods may use atransposase, such as a MuA transposase.

The sample may comprise T-cell DNA.

The sample may comprise non-target polynucleotides. In one embodiment,the target polynucleotide and the non-target polynucleotides may bederived from the same gene or genome.

Monitoring Interaction of Complex with Pore

The method comprises monitoring for the presence or absence of an effectresulting from the interaction of the complex formed by the guidepolynucleotide, the polynucleotide-guided effector protein and thetarget polynucleotide with the transmembrane pore to determine thepresence or absence of the complex. The effect is indicative of thecomplex formed by the guide polynucleotide, the polynucleotide-guidedeffector protein and the target polynucleotide interacting with thetransmembrane pore. The effect may be caused by the translocationthrough the pore of an adaptor attached to one of the components of thecomplex, the target polynucleotide or the guide polynucleotide. Theeffect is indicative of the translocation through the pore of an adaptorattached to one of the components of the complex, the targetpolynucleotide or the guide polynucleotide.

The effect may be monitored using an electrical measurement and/or anoptical measurement. In this case, the effect is a measured change ormeasured changes in an electrical or optical quantity.

The electrical measurement may be a current measurement, an impedancemeasurement, a tunnelling measurement or a field effect transistor (FET)measurement.

The effect may be a change in ion flow through the transmembrane poreresulting in a change in current, resistance or a change in an opticalproperty. The effect may be electron tunneling across the transmembranepore. The effect may be a change in potential due to the interaction ofthe complex with the transmembrane pore wherein the effect is monitoredusing localized potential sensor in a FET measurement.

Adaptor

The adaptor may comprise at least one single stranded polynucleotide ornon-polynucleotide region. Single stranded polynucleotides are usefulbecause they can pass through the pore and can easily be divided into atleast two different regions that affect the current flowing through thepore in different ways. For instance, different regions of apolynucleotide having different sequences typically affect the currentflowing through the pore in different ways. The at least two differentregions preferably correspond to at least two stretches of differentnucleotides. For instance, the single stranded polynucleotide region maycomprise a stretch of adenine nucleotides and a stretch of abasicnucleotides. Each stretch will affect the current flowing through thepore in a different way.

Alternatively, the at least two stretches of different nucleotides aredifferent polynucleotide barcodes. Polynucleotide barcodes arewell-known in the art (Kozarewa, I. et al., (2011), Methods Mol. Biol.733, p 279-298). A barcode is a specific sequence of polynucleotide thataffects the current flowing through the pore in a specific and knownmanner.

The adaptor may comprise a double-stranded polynucleotide that cannotpass through the pore. The presence of such a double stranded region maydelay the adaptor from moving through the pore as one of the strands inthe region is stripped from the probe under the influence of thepotential. Such a delay produces a detectable signal, for example achange in the current flowing through the pore. The length of the doublestranded region may be varied between different polynucleotide adpatorssuch that the length of the delay can be used to identify the adaptorinteracting with the pore. Typical lengths of the double stranded regionare from about 4 to about 50 base pairs, such as from 5, 6, 7, 8, 9 or10 to 20, 30 or 40 base pairs, or any integer between 4 and 50.

Including one or more double stranded polynucleotide regions in theadaptor increases the number of possible signals that can be obtainedfrom a population of adaptors in the panel of guide polynucleotides andhence increases the number of target polynucleotides that can be assayedusing the method of the invention.

A double stranded polynucleotide region may, for example, be used tohold a specific region of the adaptor, such as a barcode that isindicative of the guide polynucleotide, in the barrel or channel of thepore so that it may be read in accordance with the invention.

The adaptor may comprise a nucleotide sequence. A nucleotide typicallycontains a nucleobase, a sugar and at least one phosphate group. Thenucleobase is typically heterocyclic. Nucleobases include, but are notlimited to, purines and pyrimidines and more specifically adenine,guanine, thymine, uracil and cytosine. The sugar is typically a pentosesugar. Nucleotide sugars include, but are not limited to, ribose anddeoxyribose. The nucleotide is typically a ribonucleotide ordeoxyribonucleotide. The nucleotide typically contains a monophosphate,diphosphate or triphosphate. Phosphates may be attached on the 5′ or 3′side of a nucleotide.

Nucleotides include, but are not limited to, adenosine monophosphate(AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP),guanosine monophosphate (GMP), guanosine diphosphate (GDP), guanosinetriphosphate (GTP), thymidine monophosphate (TMP), thymidine diphosphate(TDP), thymidine triphosphate (TTP), uridine monophosphate (UMP),uridine diphosphate (UDP), uridine triphosphate (UTP), cytidinemonophosphate (CMP), cytidine diphosphate (CDP), cytidine triphosphate(CTP), 5-methylcytidine monophosphate, 5-methylcytidine diphosphate,5-methylcytidine triphosphate, 5-hydroxymethylcytidine monophosphate,5-hydroxymethylcytidine diphosphate, 5-hydroxymethylcytidinetriphosphate, cyclic adenosine monophosphate (cAMP), cyclic guanosinemonophosphate (cGMP), deoxyadenosine monophosphate (dAMP),deoxyadenosine diphosphate (dADP), deoxyadenosine triphosphate (dATP),deoxyguanosine monophosphate (dGMP), deoxyguanosine diphosphate (dGDP),deoxyguanosine triphosphate (dGTP), deoxythymidine monophosphate (dTMP),deoxythymidine diphosphate (dTDP), deoxythymidine triphosphate (dTTP),deoxyuridine monophosphate (dUMP), deoxyuridine diphosphate (dUDP),deoxyuridine triphosphate (dUTP), deoxycytidine monophosphate (dCMP),deoxycytidine diphosphate (dCDP) and deoxycytidine triphosphate (dCTP),5-methyl-2′-deoxycytidine monophosphate, 5-methyl-2′-deoxycytidinediphosphate, 5-methyl-2′-deoxycytidine triphosphate,5-hydroxymethyl-2′-deoxycytidine monophosphate,5-hydroxymethyl-2′-deoxycytidine diphosphate and5-hydroxymethyl-2′-deoxycytidine triphosphate. The nucleotides in theadaptor are preferably selected from AMP, TMP, GMP, UMP, dAMP, dTMP,dGMP or dCMP. The nucleotides may be abasic (e.g. lack a nucleobase).The nucleotides may contain additional modifications. In particular,suitable modified nucleotides include, but are not limited to, 2′aminopyrimidines (such as 2′-amino cytidine and 2′-amino uridine),2′-hyrdroxyl purines (such as, 2′-fluoro pyrimidines (such as2′-fluorocytidine and 2′fluoro uridine), hydroxyl pyrimidines (such as5′-α-P-borano uridine), 2′-O-methyl nucleotides (such as 2′-O-methyladenosine, 2′-O-methyl guanosine, 2′-O-methyl cytidine and 2′-O-methyluridine), 4′-thio pyrimidines (such as 4′-thio uridine and 4′-thiocytidine) and nucleotides have modifications of the nucleobase (such as5-pentynyl-2′-deoxy uridine, 5-(3-aminopropyl)-uridine and1,6-diaminohexyl-N-5-carbamoylmethyl uridine).

The adaptor may comprise one or more different nucleotide species. Forinstance, T k-mers (e.g. k-mers in which the central nucleotide isthymine-based, such as TTA, GTC, GTG and CTA) typically have the lowestcurrent states. Modified versions of T nucleotides may be introducedinto the modified polynucleotide to reduce the current states furtherand thereby increase the total current range seen when the adaptor movesthrough the pore.

G k-mers (e.g. k-mers in which the central nucleotide is guanine-based,such as TGA, GGC, TGT and CGA) tend to be strongly influenced by othernucleotides in the k-mer and so modifying the G nucleotides in themodified polynucleotide may help them to have more independent currentpositions.

Including three copies of the same nucleotide species instead of threedifferent species may facilitate characterisation because it is thenonly necessary to map, for example, 3-nucleotide k-mers in the modifiedpolynucleotide. However, such modifications do reduce the informationprovided by the adaptor.

Including one or more nucleotide species with abasic nucleotides in theadaptor results in characteristic current spikes. This allows the clearhighlighting of the positions of the one or more nucleotide species inthe adaptor.

The nucleotide species in the adaptor may comprise a chemical atom orgroup such as a propynyl group, a thio group, an oxo group, a methylgroup, a hydroxymethyl group, a formyl group, a carboxy group, acarbonyl group, a benzyl group, a propargyl group or a propargylaminegroup. The chemical group or atom may be or may comprise a fluorescentmolecule, biotin, digoxigenin, DNP (dinitrophenol), a photo-labilegroup, an alkyne, DBCO, azide, free amino group, a redox dye, a mercuryatom or a selenium atom.

The adaptor may comprise a nucleotide species comprising a halogen atom.The halogen atom may be attached to any position on the differentnucleotide species, such as the nucleobase and/or the sugar. The halogenatom is preferably fluorine (F), chlorine (Cl), bromine (Br) or iodine(I). The halogen atom is most preferably F or I.

The adaptor may comprise a sequence capable of forming a quadruplex. Aquadruplex is a three dimensional structure formed from four sequencestrands. The quadruplex is incapable of translocating or moving throughthe narrowest part of the pore. The quadruplex is wider than thenarrowest part of the pore. For example, the narrowest part of wild-typeα-HL pore is 1.3 nm is diameter. The narrowest part of α-HL-NN pore is1.5 nm in diameter. If either of these pores is used in the invention,the quadruplex preferably has a width of greater than 1.3 nm, such asgreater than 1.5 nm, such as greater than 2 nm, greater than 3 nm orgreater than 5 nm. A person skilled in the art will be able to design asuitably sized quadruplex for the pore being used. Thequadruplex-forming sequence is capable of translocating or movingthrough the narrowest part of the pore when it is not formed into aquadruplex. The quadruplex-forming sequence is preferably apolynucleotide. It may be any of the polynucleotides discussed herein.

The quadruplex may be any type of quadruplex. The quadruplex may be anintermolecular quadruplex, such as a bimolecular quadruplex or atetramolecular quadruplex. The quadruplex-forming sequence is preferablycapable of forming an intramolecular quadruplex.

The quadruplex-forming sequence is preferably capable of formingG-quadruplexes (also known as G-tetrads or G4-DNA). These arepolynucleotide sequences that are rich in guanine and are capable offorming a four-stranded structure. Four guanine bases can associatethrough Hoogsteen hydrogen bonding to form a square planar structurecalled a guanine tetrad, and two or more guanine tetrads can stack ontop of each other to form a G-quadruplex. The quadruplex structure isfurther stabilized by the presence of a cation, especially potassium,which sits in a central channel between each pair of tetrads. FormingG-quadruplexes is well known in the art (Marathias and Bolton, NucleicAcids Research, 2000; 28(9): 1969-1977; Kankia and Marky, J. Am. Chem.Soc. 2001, 123, 10799-10804; and Marusic et al., Nucleic Acids Research,2012, 1-11).

The quadruplex-forming sequence more preferably comprises the sequenceGa followed by Nb followed by Gc followed by Nd followed by Ge followedby Nf followed by Gg, wherein G is a nucleotide comprising guanine,wherein a, c, e and g are independently selected from 1, 2, 3, 4 and 5,wherein N is any nucleotide and wherein b, d and f are from 2 to 50. Thevalues of a, c, e and g may be identical. G is preferably guanosinemonophosphate (GMP), cyclic guanosine monophosphate (cGMP),deoxyguanosine monophosphate (dGMP), dideoxyguanosine monophosphate,N2-methyl-GMP, N2-methyl-cGMP, N2-methyl-dGMP,N2-methyl-dideoxyguanosine monophosphate, N2-methyl-06-methyl-GMP,N2-methyl-06-methyl-cGMP, N2-methyl-06-methyl-dGMP,N2-methyl-06-methyl-dideoxyguanosine monophosphate, 2′-O-methyl-GMP,2′-O-methyl-cGMP, 2′-O-methyl-dGMP, 2′-O-methyl-dideoxyguanosinemonophosphate, 6-thio-GMP, 6-thio-cGMP, 6-thio-dGMP,6-thio-dideoxyguanosine monophosphate, 7-methyl-GMP, 7-methyl-cGMP,7-methyl-dGMP, 7-methyl-dideoxyguanosine monophosphate, 7-deaza-GMP,7-deaza-cGMP, 7-deaza-dGMP, 7-deaza-dideoxyguanosine monophosphate,8-oxo-GMP, 8-oxo-cGMP, 8-oxo-dGMP or 8-oxo-dideoxyguanosinemonophosphate.

Suitable quadruplex-forming sequences are disclosed in WO 2014/072703.

Since the quadruplex is incapable of translocating through the narrowestpart of the pore, it acts like a brake and holds another, typicallysingle stranded, region of the adaptor or guide polynucleotide in thenarrowest part of the pore. The adaptor region then results in adistinctive current which identifies the guide polynucleotide and hencethe target polynucleotide in the complex. After a short while, thequadruplex will typically destabilise under the influence of the appliedpotential and unfold. The braking action of the quadruplex is thereforetypically temporary. The unfolded quadruplex-forming sequence typicallytranslocates or moves through the pore under the influence of theapplied potential.

Coupling

The complex comprising a guide polynucleotide, a polynucleotide-guidedeffector protein and a target polynucleotide may be coupled to themembrane using an anchor. One or more anchors may be used to couple thecomplex to the membrane. Typically the one or more anchors are presenton the same component of the complex, such as on the targetpolynucleotide, the guide polynucleotide or the polynucleotide-guidedeffector protein. Alternatively the one or more anchors may be presenton different components such as on the guide polynucleotide and thepolynucleotide-guided effector protein.

If the membrane is an amphiphilic layer, such as a triblock copolymermembrane, the one or more anchors preferably comprise a polypeptideanchor and/or a hydrophobic anchor that can be inserted into themembrane. The hydrophobic anchor is preferably a lipid, fatty acid,sterol, carbon nanotube, polypeptide, protein or amino acid, for examplecholesterol, palmitate or tocopherol. In preferred embodiments, the oneor more anchors are not the pore.

The components of the membrane, such as the amphiphilic molecules,copolymer or lipids, may be chemically-modified or functionalised toform the one or more anchors. Examples of suitable chemicalmodifications and suitable ways of functionalising the components of themembrane are discussed in more detail below. Any proportion of themembrane components may be functionalised, for example at least 0.01%,at least 0.1%, at least 1%, at least 10%, at least 25%, at least 50% or100%.

The one or more anchors preferably comprise a linker. The one or moreanchors may comprise one or more, such as 2, 3, 4 or more, linkers. Onelinker may be used to couple both a guide polynucleotide and apolynucleotide-guided effector protein to the membrane.

Preferred linkers include, but are not limited to, polymers, such aspolynucleotides, polyethylene glycols (PEGs), polysaccharides andpolypeptides. These linkers may be linear, branched or circular. Forinstance, the linker may be a circular polynucleotide. The targetpolynucleotide or the guide polynucleotide may hybridise to acomplementary sequence on the circular polynucleotide linker.

The one or more anchors or one or more linkers may comprise a componentthat can be cut or broken down, such as a restriction site or aphotolabile group.

Functionalised linkers and the ways in which they can couple moleculesare known in the art. For instance, linkers functionalised withmaleimide groups will react with and attach to cysteine residues inproteins.

Cross-linkage of polynucleotides can be avoided using a “lock and key”arrangement. Only one end of each linker may react together to form alonger linker and the other ends of the linker each react with thepolynucleotide or membrane respectively. Such linkers are described inWO 2010/086602.

The use of a linker is preferred in the sequencing methods of theinvention. If a polynucleotide is permanently coupled directly to themembrane in the sense that it does not uncouple when interacting withthe pore, then some sequence data will be lost as the sequencing runcannot continue to the end of the polynucleotide due to the distancebetween the membrane and the pore. If a linker is used, then thepolynucleotide can be processed to completion.

The coupling may be permanent or stable. In other words, the couplingmay be such that the complex remains coupled to the membrane wheninteracting with the pore.

The coupling may be transient. In other words, the coupling may be suchthat the complex may decouple from the membrane when interacting withthe pore. For complex detection and polynucleotide sequencing, thetransient nature of the coupling is preferred. If a permanent or stablelinker is attached directly to either the 5′ or 3′ end of apolynucleotide and the linker is shorter than the distance between themembrane and the channel of the transmembrane pore, then some sequencedata will be lost as the sequencing run cannot continue to the end ofthe polynucleotide. If the coupling is transient, then when the coupledend randomly becomes free of the membrane, then the polynucleotide canbe processed to completion. Chemical groups that form permanent/stableor transient links are discussed in more detail below. The complex maybe transiently coupled to an amphiphilic layer or triblock copolymermembrane using cholesterol or a fatty acyl chain. Any fatty acyl chainhaving a length of from 6 to 30 carbon atom, such as hexadecanoic acid,may be used.

In preferred embodiments, anchor couples the complex to an amphiphiliclayer such as a triblock copolymer membrane or lipid bilayer. Couplingof nucleic acids to synthetic lipid bilayers has been carried outpreviously with various different tethering strategies. These aresummarised in Table 1 below.

TABLE 1 Anchor Type of comprising coupling Reference Thiol StableYoshina-Ishii, C. and S. G. Boxer (2003). “Arrays of mobile tetheredvesicles on supported lipid bilayers.” J Am Chem Soc 125(13): 3696-7.Biotin Stable Nikolov, V., R. Lipowsky, et al. (2007). “Behavior ofgiant vesicles with anchored DNA molecules.” Biophys J 92(12): 4356-68Cholesterol Transient Pfeiffer, I. and F. Hook (2004). “Bivalentcholesterol-based coupling of oligonucletides to lipid membraneassemblies.” J Am Chem Soc 126(33): 10224-5 Surfactant (e.g. Stable vanLengerich, B., R. J. Rawle, et al. Lipid, “Covalent attachment of lipidvesicles to a Palmitate, fluid-supported bilayer allows observation ofetc) DNA-mediated vesicle interactions.” Langmuir 26(11): 8666-72

Synthetic polynucleotides and/or linkers may be functionalised using amodified phosphoramidite in the synthesis reaction, which is easilycompatible for the direct addition of suitable anchoring groups, such ascholesterol, tocopherol, palmitate, thiol, lipid and biotin groups.These different attachment chemistries give a suite of options forattachment to polynucleotides. Each different modification group couplesthe polynucleotide in a slightly different way and coupling is notalways permanent so giving different dwell times for the polynucleotideto the membrane.

Coupling of polynucleotides to a linker or to a functionalised membranecan also be achieved by a number of other means provided that acomplementary reactive group or an anchoring group can be added to thepolynucleotide. The addition of reactive groups to either end of apolynucleotide has been reported previously. A thiol group can be addedto the 5′ of ssDNA or dsDNA using T4 polynucleotide kinase and ATPγS(Grant, G. P. and P. Z. Qin (2007). “A facile method for attachingnitroxide spin labels at the 5′ terminus of nucleic acids.” NucleicAcids Res 35(10): e77). An azide group can be added to the 5′-phosphateof ssDNA or dsDNA using T4 polynucleotide kinase andγ-[2-Azidoethyl]-ATP or γ-[6-Azidohexyl]-ATP. Using thiol or Clickchemistry a tether, containing either a thiol, iodoacetamide OPSS ormaleimide group (reactive to thiols) or a DIBO (dibenzocyclooxtyne) oralkyne group (reactive to azides), can be covalently attached to thepolynucleotide. A more diverse selection of chemical groups, such asbiotin, thiols and fluorophores, can be added using terminal transferaseto incorporate modified oligonucleotides to the 3′ of ssDNA (Kumar, A.,P. Tchen, et al. (1988). “Nonradioactive labeling of syntheticoligonucleotide probes with terminal deoxynucleotidyl transferase.” AnalBiochem 169(2): 376-82). Streptavidin/biotin and/orstreptavidin/desthiobiotin coupling may be used for any otherpolynucleotide. It may also be possible that anchors may be directlyadded to polynucleotides using terminal transferase with suitablymodified nucleotides (e.g. cholesterol or palmitate).

The one or more anchors may couple the complex to the membrane viahybridisation. The hybridisation may be between the one or more anchorsand the target polynucleotide or guide polynucleotide, within the one ormore anchors or between the one or more anchors and the membrane.Hybridisation in the one or more anchors allows coupling in a transientmanner as discussed above. For instance, a linker may comprise two ormore polynucleotides, such as 3, 4 or 5 polynucleotides, hybridisedtogether. The one or more anchors may hybridise to the target or guidepolynucleotide. The one or more anchors may hybridise directly to thetarget or guide polynucleotide, directly to a Y adaptor and/or leadersequence attached to the polynucleotide or directly to a hairpin loopadaptor attached to the polynucleotide. Alternatively, the one or moreanchors may be hybridised to one or more, such as 2 or 3, intermediatepolynucleotides (or “splints”) which are hybridised to thepolynucleotide, to a Y adaptor and/or leader sequence attached to thepolynucleotide or to a hairpin loop adaptor attached to thepolynucleotide.

The one or more anchors may comprise a single stranded or doublestranded polynucleotide. One part of the anchor may be ligated to asingle stranded or double stranded polynucleotide analyte. Ligation ofshort pieces of ssDNA have been reported using T4 RNA ligase I (Troutt,A. B., M. G. McHeyzer-Williams, et al. (1992). “Ligation-anchored PCR: asimple amplification technique with single-sided specificity.” Proc NatlAcad Sci USA 89(20): 9823-5). Alternatively, either a single stranded ordouble stranded polynucleotide can be ligated to a double strandedpolynucleotide and then the two strands separated by thermal or chemicaldenaturation. To a double stranded polynucleotide, it is possible to addeither a piece of single stranded polynucleotide to one or both of theends of the duplex, or a double stranded polynucleotide to one or bothends. For addition of single stranded polynucleotides to the doublestranded polynucleotide, this can be achieved using T4 RNA ligase I asfor ligation to other regions of single stranded polynucleotides. Foraddition of double stranded polynucleotides to a double strandedpolynucleotide then ligation can be “blunt-ended”, with complementary 3′dA/dT tails on the polynucleotide and added polynucleotide respectively(as is routinely done for many sample preparation applications toprevent concatemer or dimer formation) or using “sticky-ends” generatedby restriction digestion of the polynucleotide and ligation ofcompatible adapters. Then, when the duplex is melted, each single strandwill have either a 5′ or 3′ modification if a single strandedpolynucleotide was used for ligation or a modification at the 5′ end,the 3′ end or both if a double stranded polynucleotide was used forligation.

If the polynucleotide is a synthetic strand, the one or more anchors canbe incorporated during the chemical synthesis of the polynucleotide. Forinstance, the polynucleotide can be synthesised using a primer having areactive group attached to it.

Adenylated polynucleotides are intermediates in ligation reactions,where an adenosine-monophosphate is attached to the 5′-phosphate of thepolynucleotide. Various kits are available for generation of thisintermediate, such as the 5′ DNA Adenylation Kit from NEB. Bysubstituting ATP in the reaction for a modified nucleotide triphosphate,then addition of reactive groups (such as thiols, amines, biotin,azides, etc) to the 5′ of a polynucleotide can be possible. It may alsobe possible that anchors could be directly added to polynucleotidesusing a 5′ DNA adenylation kit with suitably modified nucleotides (e.g.cholesterol or palmitate).

A common technique for the amplification of sections of genomic DNA isusing polymerase chain reaction (PCR). Here, using two syntheticoligonucleotide primers, a number of copies of the same section of DNAcan be generated, where for each copy the 5′ of each strand in theduplex will be a synthetic polynucleotide. Single or multiplenucleotides can be added to 3′ end of single or double stranded DNA byemploying a polymerase. Examples of polymerases which could be usedinclude, but are not limited to, Terminal Transferase, Klenow and E.coli Poly(A) polymerase). By substituting ATP in the reaction for amodified nucleotide triphosphate then anchors, such as a cholesterol,thiol, amine, azide, biotin or lipid, can be incorporated into doublestranded polynucleotides. Therefore, each copy of the amplifiedpolynucleotide will contain an anchor.

Ideally, the polynucleotide is coupled to the membrane without having tofunctionalise the polynucleotide. This can be achieved by coupling theone or more anchors, such as a polynucleotide binding protein or achemical group, to the membrane and allowing the one or more anchors tointeract with the polynucleotide or by functionalizing the membrane. Theone or more anchors may be coupled to the membrane by any of the methodsdescribed herein. In particular, the one or more anchors may compriseone or more linkers, such as maleimide functionalised linkers. In thisembodiment, the polynucleotide is typically RNA, DNA, PNA, TNA or LNAand may be double or single stranded. This embodiment is particularlysuited to genomic DNA polynucleotides.

The one or more anchors can comprise any group that couples to, binds toor interacts with single or double stranded polynucleotides, specificnucleotide sequences within the polynucleotide or patterns of modifiednucleotides within the polynucleotide, or any other ligand that ispresent on the polynucleotide.

Suitable binding proteins for use in anchors include, but are notlimited to, E. coli single stranded binding protein, P5 single strandedbinding protein, T4 gp32 single stranded binding protein, the TOPO VdsDNA binding region, human histone proteins, E. coli HU DNA bindingprotein and other archaeal, prokaryotic or eukaryotic single stranded ordouble stranded polynucleotide (or nucleic acid) binding proteins,including those listed below.

The specific nucleotide sequences could be sequences recognised bytranscription factors, ribosomes, endonucleases, topoisomerases orreplication initiation factors. The patterns of modified nucleotidescould be patterns of methylation or damage.

The one or more anchors can comprise any group which couples to, bindsto, intercalates with or interacts with a polynucleotide. The group mayintercalate or interact with the polynucleotide via electrostatic,hydrogen bonding or Van der Waals interactions. Such groups include alysine monomer, poly-lysine (which will interact with ssDNA or dsDNA),ethidium bromide (which will intercalate with dsDNA), universal bases oruniversal nucleotides (which can hybridise with any polynucleotide) andosmium complexes (which can react to methylated bases). A polynucleotidemay therefore be coupled to the membrane using one or more universalnucleotides attached to the membrane. Each universal nucleotide may becoupled to the membrane using one or more linkers. The universalnucleotide preferably comprises one of the following nucleobases:hypoxanthine, 4-nitroindole, 5-nitroindole, 6-nitroindole, formylindole,3-nitropyrrole, nitroimidazole, 4-nitropyrazole, 4-nitrobenzimidazole,5-nitroindazole, 4-aminobenzimidazole or phenyl (C6-aromatic ring). Theuniversal nucleotide more preferably comprises one of the followingnucleosides: 2′-deoxyinosine, inosine, 7-deaza-2′-deoxyinosine,7-deaza-inosine, 2-aza-deoxyinosine, 2-aza-inosine, 2-O′-methylinosine,4-nitroindole 2′-deoxyribonucleoside, 4-nitroindole ribonucleoside,5-nitroindole 2′-deoxyribonucleoside, 5-nitroindole ribonucleoside,6-nitroindole 2′-deoxyribonucleoside, 6-nitroindole ribonucleoside,3-nitropyrrole 2′-deoxyribonucleoside, 3-nitropyrrole ribonucleoside, anacyclic sugar analogue of hypoxanthine, nitroimidazole2′-deoxyribonucleoside, nitroimidazole ribonucleoside, 4-nitropyrazole2′-deoxyribonucleoside, 4-nitropyrazole ribonucleoside,4-nitrobenzimidazole 2′-deoxyribonucleoside, 4-nitrobenzimidazoleribonucleoside, 5-nitroindazole 2′-deoxyribonucleoside, 5-nitroindazoleribonucleoside, 4-aminobenzimidazole 2′-deoxyribonucleoside,4-aminobenzimidazole ribonucleoside, phenyl C-ribonucleoside, phenylC-2′-deoxyribosyl nucleoside, 2′-deoxynebularine, 2′-deoxyisoguanosine,K-2′-deoxyribose, P-2′-deoxyribose and pyrrolidine. The universalnucleotide more preferably comprises 2′-deoxyinosine. The universalnucleotide is more preferably IMP or dIMP. The universal nucleotide ismost preferably dPMP (2′-Deoxy-P-nucleoside monophosphate) or dKMP(N6-methoxy-2, 6-diaminopurine monophosphate).

The one or more anchors may couple to (or bind to) the polynucleotidevia Hoogsteen hydrogen bonds (where two nucleobases are held together byhydrogen bonds) or reversed Hoogsteen hydrogen bonds (where onenucleobase is rotated through 180° with respect to the othernucleobase). For instance, the one or more anchors may comprise one ormore nucleotides, one or more oligonucleotides or one or morepolynucleotides which form Hoogsteen hydrogen bonds or reversedHoogsteen hydrogen bonds with the polynucleotide. These types ofhydrogen bonds allow a third polynucleotide strand to wind around adouble stranded helix and form a triplex. The one or more anchors maycouple to (or bind to) a double stranded polynucleotide by forming atriplex with the double stranded duplex.

In this embodiment at least 1%, at least 10%, at least 25%, at least 50%or 100% of the membrane components may be functionalised.

Where the one or more anchors comprise a protein, they may be able toanchor directly into the membrane without further functionalisation, forexample if it already has an external hydrophobic region which iscompatible with the membrane. Examples of such proteins include, but arenot limited to, transmembrane proteins, intramembrane proteins andmembrane proteins. Alternatively the protein may be expressed with agenetically fused hydrophobic region which is compatible with themembrane. Such hydrophobic protein regions are known in the art.

The one or more anchors are preferably mixed with the polynucleotidebefore delivery to the membrane, but the one or more anchors may becontacted with the membrane and subsequently contacted with thepolynucleotide.

In another aspect the polynucleotide may be functionalised, usingmethods described above, so that it can be recognised by a specificbinding group. Specifically the polynucleotide may be functionalisedwith a ligand such as biotin (for binding to streptavidin), amylose (forbinding to maltose binding protein or a fusion protein), Ni-NTA (forbinding to poly-histidine or poly-histidine tagged proteins) or peptides(such as an antigen).

According to a preferred embodiment, the one or more anchors may be usedto couple a polynucleotide to the membrane when the polynucleotide isattached to a leader sequence which preferentially threads into thepore. Preferably, the polynucleotide is attached (such as ligated) to aleader sequence which preferentially threads into the pore. Such aleader sequence may comprise a homopolymeric polynucleotide or an abasicregion. The leader sequence is typically designed to hybridise to theone or more anchors either directly or via one or more intermediatepolynucleotides (or splints). In such instances, the one or more anchorstypically comprise a polynucleotide sequence which is complementary to asequence in the leader sequence or a sequence in the one or moreintermediate polynucleotides (or splints). In such instances, the one ormore splints typically comprise a polynucleotide sequence which iscomplementary to a sequence in the leader sequence.

Any of the methods discussed above for coupling polynucleotides tomembranes, such as amphiphilic layers, can of course be applied to otherpolynucleotide and membrane combinations. In some embodiments, an aminoacid, peptide, polypeptide or protein is coupled to an amphiphiliclayer, such as a triblock copolymer layer or lipid bilayer. Variousmethodologies for the chemical attachment of such polynucleotides areavailable. An example of a molecule used in chemical attachment is EDC(1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride). Reactivegroups can also be added to the 5′ of polynucleotides using commerciallyavailable kits (Thermo Pierce, Part No. 22980). Suitable methodsinclude, but are not limited to, transient affinity attachment usinghistidine residues and Ni-NTA, as well as more robust covalentattachment by reactive cysteines, lysines or non natural amino acids.

Leader Sequence

The leader sequence typically comprises a polymer. The polymer ispreferably negatively charged. The polymer is preferably apolynucleotide, such as DNA or RNA, a modified polynucleotide (such asabasic DNA), PNA, LNA, polyethylene glycol (PEG) or a polypeptide. Theleader preferably comprises a polynucleotide and more preferablycomprises a single stranded polynucleotide. The single stranded leadersequence most preferably comprises a single strand of DNA, such as apoly dT section. The leader sequence preferably comprises the one ormore spacers.

The leader sequence can be any length, but is typically 10 to 150nucleotides in length, such as from 20 to 150 nucleotides in length. Thelength of the leader typically depends on the transmembrane pore used inthe method.

The leader sequence preferentially threads into the transmembrane poreand thereby facilitates the movement of polynucleotide through the pore.The leader sequence can also be used to link the polynucleotide to theone or more anchors as discussed herein.

Sequencing Adaptors—Y Adaptors

Y-adaptors for use in nanopore sequencing are known in the art. A Yadaptor typically comprises (a) a double stranded region and (b) asingle stranded region or a region that is not complementary at theother end. A Y adaptor may be described as having an overhang if itcomprises a single stranded region. The presence of a non-complementaryregion in the Y adaptor gives the adaptor its Y shape since the twostrands typically do not hybridise to each other unlike the doublestranded portion. The Y adaptor may comprise one or more anchors.

The Y adaptor preferably comprises a leader sequence whichpreferentially threads into the pore.

The Y adaptor and/or the hairpin loop may be ligated to thepolynucleotide using any method known in the art. One or both of theadaptors may be ligated using a ligase, such as T4 DNA ligase, E. coliDNA ligase, Taq DNA ligase, Tma DNA ligase and 9° N DNA ligase.Alternatively, the adaptors may be added to the polynucleotide using themethods discussed below.

In a preferred embodiment, the method comprises modifying the doublestranded polynucleotides in the sample so that they comprise the Yadaptor at one end and the hairpin loop at the other end. Any manner ofmodification can be used. The method preferably comprises modifying thedouble stranded target polynucleotide.

The double stranded polynucleotide may be provided with adaptors, suchas Y adaptors and hairpin loops, or anchors by contacting thepolynucleotide with a MuA transposase and a population of doublestranded MuA substrates. The transposase fragments the double strandedpolynucleotide and ligates MuA substrates to one or both ends of thefragments. This produces a plurality of modified double strandedpolynucleotides comprising an adaptor or anchor. The modified doublestranded polynucleotides may then be investigated using the method ofthe invention.

These MuA based methods are disclosed in WO 2015/022544 and WO2016/059363. They are also discussed in detail in WO2015/150786.

A double stranded polynucleotide may be provided with a Y adaptor at oneend and a hairpin loop at the other end. For example, a proportion ofthe MuA substrates in the population may be Y adaptors comprising aleader sequence and a proportion of the substrates in the population maybe hairpin loops.

The Y adaptor may comprise a capture sequence, affinity tag or poretether that is revealed when a double stranded region to which theadaptor is attached is unwound. The capture sequence or tag functions toprevent the second strand of a double stranded polynucleotide fromdiffusing away from a nanopore when the double stranded polynucleotideis unwound as the first strand of the double stranded polynucleotidepasses through a pore, wherein the pore binds to the tether or is taggedwith an oligonucleotide comprising a sequence that is complementary tothe capture sequence in the Y adaptor, an affinity partner of the tag onthe Y-adaptor.

Hairpin Loops

Hairpin loop adaptors for use in nanopore sequencing are known in theart. A hairpin loop may be provided at one end of a double strandedpolynucleotide, the method preferably further comprises providing thepolynucleotide with a hairpin loop at one end of the polynucleotide. Thetwo strands of the polynucleotide may be joined at one end with thehairpin loop.

Suitable hairpin loops can be designed using methods known in the art.The hairpin loop may be any length. The hairpin loop is typically 110 orfewer nucleotides, such as 100 or fewer nucleotides, 90 or fewernucleotides, 80 or fewer nucleotides, 70 or fewer nucleotides, 60 orfewer nucleotides, 50 or fewer nucleotides, 40 or fewer nucleotides, 30or fewer nucleotides, 20 or fewer nucleotides or 10 or fewernucleotides, in length. The hairpin loop is preferably from about 1 to110, from 2 to 100, from 5 to 80 or from 6 to 50 nucleotides in length.Longer lengths of the hairpin loop, such as from 50 to 110 nucleotides,are preferred if the loop is involved in the differential selectabilityof the adaptor. Similarly, shorter lengths of the hairpin loop, such asfrom 1 to 5 nucleotides, are preferred if the loop is not involved inthe selectable binding as discussed below.

The hairpin loop may be provided at either end of the polynucleotide,e.g. the 5′ or the 3′ end. The hairpin loop may be ligated to thepolynucleotide using any method known in the art. The hairpin loop maybe ligated using a ligase, such as T4 DNA ligase, E. coli DNA ligase,Taq DNA ligase, Tma DNA ligase and 9° N DNA ligase.

In a method of characterizing a polynucleotide by sequencing, the twostrands of a double stranded polynucleotide joined by a hairpin loop maybe separated using any method known in the art. The two strands of thepolynucleotide are then moved through the pore one strand at a time.Linking and interrogating both strands on a double stranded construct inthis way increases the efficiency and accuracy of characterisation.

The hairpin loop preferably comprises a selectable binding moiety. Thisallows the polynucleotide to be purified or isolated. A selectablebinding moiety is a moiety that can be selected on the basis of itsbinding properties. Hence, a selectable binding moiety is preferably amoiety that specifically binds to a surface. A selectable binding moietyspecifically binds to a surface if it binds to the surface to a muchgreater degree than any other moiety used in the invention. In preferredembodiments, the moiety binds to a surface to which no other moiety usedin the invention binds.

Suitable selective binding moieties are known in the art. Preferredselective binding moieties include, but are not limited to, biotin, apolynucleotide sequence, antibodies, antibody fragments, such as Fab andScSv, antigens, polynucleotide binding proteins, poly histidine tailsand GST tags. The most preferred selective binding moieties are biotinand a selectable polynucleotide sequence. Biotin specifically binds to asurface coated with avidins. Selectable polynucleotide sequencesspecifically bind (e.g. hybridise) to a surface coated with homologussequences. Alternatively, selectable polynucleotide sequencesspecifically bind to a surface coated with polynucleotide bindingproteins.

The hairpin loop and/or the selectable binding moiety may comprise aregion that can be cut, nicked, cleaved or hydrolysed. Such a region canbe designed to allow the polynucleotide to be removed from the surfaceto which it is bound following purification or isolation. Suitableregions are known in the art. Suitable regions include, but are notlimited to, an RNA region, a region comprising desthiobiotin andstreptavidin, a disulphide bond and a photocleavable region.

Beads

A bead, typically a microparticle, may be used to deliver the complex tothe transmembrane pore. This is described in WO 2016/059375. Any numberof microparticles can be used in the method of the invention. Forinstance, the method may use a single microparticle or 2, 3, 4, 5, 6, 7,8, 9, 10, 20, 30, 50, 100, 1,000, 5,000, 10,000, 100,000, 500,000 or1,000,000 or more microparticles. If two or more microparticles areused, the microparticles may be the same. Alternatively, a mixture ofdifferent microparticles may be used.

Each microparticle may have one complex attached. Alternatively, eachmicroparticle may have two or more complexes, such as 3 or more, 4 ormore, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more,20 or more, 30 or more, 50 or more, 100 or more, 500 or more, 1,000 ormore, 5,000 or more, 10,000 or more, 100,000 or more, 1000,000 or moreor 5000,000 or more polynucleotides, attached. A microparticle may besubstantially or completed coated or covered with complexes. Amicroparticle may have a complex attached over substantially all of orall of its surface. A microparticle may be attached to a complex via anadaptor. The adaptor may be a Y-adaptor or a hairpin adaptor.

The complex may be attached to a microparticle via any one or more ofits components. The guide polynucleotide, the polynucleotide-guidedeffector protein and/or the target polynucleotide may be attached to themicroparticle. For example, the polynucleotide-guided effector protein,guide polynucleotide and/or the target polynucleotide may have a bindingmoiety attached that will bind to the surface of a microparticle.

Examples of suitable binding moieties include: protein binding tags(strep tag, flag tags, etc), conjugated attachments (polynucleotides,polymers, biotins, peptides) and amino acids (cysteines, Faz, etc).

A complex may be attached to two or more microparticles.

A microparticle is a microscopic particle whose size is typicallymeasured in micrometres (μm). Microparticles may also known asmicrospheres or microbeads. The microparticle may be a nanoparticle. Ananoparticle is a microscopic particle whose size is typically measuredin nanometres (nm).

A microparticle typically has a particle size of from about 0.001 μm toabout 500 μm. For instance, a nanoparticle may have a particle size offrom about 0.01 μm to about 200 μm or about 0.1 μm to about 100 μm. Moreoften, a microparticle has a particle size of from about 0.5 μm to about100 μm, or for instance from about 1 μm to about 50 μm. Themicroparticle may have a particle size of from about 1 nm to about 1000nm, such as from about 10 nm to about 500 nm, about 20 nm to about 200nm or from about 30 nm to about 100 nm.

A microparticle may be spherical or non-spherical. Sphericalmicroparticles may be called microspheres. Non-spherical particles mayfor instance be plate-shaped, needle-shaped, irregular or tubular. Theterm “particle size” as used herein means the diameter of the particleif the particle is spherical or, if the particle is non-spherical, thevolume-based particle size. The volume-based particle size is thediameter of the sphere that has the same volume as the non-sphericalparticle in question.

If two or more microparticles are used in the method, the averageparticle size of the microparticles may be any of the sizes discussedabove, such as from about 0.5 μm to about 500 μm. A population of two ormore microparticles preferably has a coefficient of variation (ratio ofthe standard deviation to the mean) of 10% or less, such as 5% or lessor 2% or less.

Any method may be used to determine the size of the microparticle.Suitable methods include, but are not limited to, flow cytometry (see,for example, Chandler et al., J Thromb Haemost. 2011 June;9(6):1216-24).

The microparticle may be formed from any material. The microparticle ispreferably formed from a ceramic, glass, silica, a polymer or a metal.The polymer may be a natural polymer, such as polyhydroxyalkanoate,dextran, polylactide, agarose, cellulose, starch or chitosan, or asynthetic polymer, such as polyurethane, polystyrene, poly(vinylchloride), silane or methacrylate. Suitable microparticles are known inthe art and are commercially available. Ceramic and glass microspheresare commercially available from 3M®. Silica and polymer microparticlesare commercially available from EPRUI Nanoparticles & Microspheres Co.Ltd. Microparticles are also commercially available from PolysciencesInc., Bangs Laboratories Inc. and Life Technologies.

The microparticle may be solid. The microparticle may be hollow. Themicroparticle may be formed from polymer fibers.

The microparticle may be derived from the kit used to extract andisolate the polynucleotide.

The surface of the microparticle may interact with and attach theanalyte. The surface may naturally interact with the analyte, such asthe polynucleotide, without functionalisation. The surface of themicroparticle is typically functionalised to facilitate attachment ofthe analyte. Suitable functionalisations are known in the art. Forinstance, the surface of the microparticle may be functionalised with apolyhistidine-tag (hexa histidine-tag, 6×His-tag, His6 tag or His-tag®),Ni-NTA, streptavidin, biotin, an oligonucleotide, a polynucleotide (suchas DNA, RNA, PNA, GNA, TNA or LNA), carboxyl groups, quaternary aminegroups, thiol groups, azide groups, alkyne groups, DIBO, lipid, FLAG-tag(FLAG octapeptide, polynucleotide binding proteins (including any ofthose discussed below), peptides, proteins, antibodies or antibodyfragments. The microparticle may also be functionalised with any of thelinkers or groups discussed herein.

The microparticle may be functionalised with a molecule or group whichspecifically binds to the polynucleotide. In this instance, thepolynucleotide which will be attached to the microparticle and deliveredto the transmembrane pore may be called the target polynucleotide. Thisallows the microparticle to select or capture the target polynucleotidefrom a sample containing other polynucleotides. A molecule or groupspecifically binds to the target polynucleotide if it binds to thetarget polynucleotide with preferential or high affinity, but does notbind or binds with only low affinity to other or differentpolynucleotides. A molecule or group binds with preferential or highaffinity if it binds with a Kd of 1×10⁻⁶ M or less, more preferably1×10⁻⁷ M or less, 5×10⁻⁸ M or less, more preferably 1×10⁻⁸ M or less ormore preferably 5×10⁻⁹ M or less. A molecule or group binds with lowaffinity if it binds with a Kd of 1×10⁻⁶ M or more, more preferably1×10⁻⁵ M or more, more preferably 1×10⁻⁴ M or more, more preferably1×10⁻³ M or more, even more preferably 1×10⁻² M or more.

Preferably, the molecule or group binds to the target polynucleotidewith an affinity that is at least 10 times, such as at least 50, atleast 100, at least 200, at least 300, at least 400, at least 500, atleast 1000 or at least 10,000 times, greater than its affinity for otherpolynucleotides. Affinity can be measured using known binding assays,such as those that make use of fluorescence and radioisotopes.Competitive binding assays are also known in the art. The strength ofbinding between peptides or proteins and polynucleotides can be measuredusing nanopore force spectroscopy as described in Hornblower et al.,Nature Methods. 4: 315-317. (2007).

The microparticle may be functionalised with an oligonucleotide or apolynucleotide which specifically hybridises to a target polynucleotideor guide polynucleotide or which comprises a portion or region which iscomplementary to a portion or region of the target polynucleotide orguide polynucleotide. This allows the microparticle to select or capturethe target polynucleotide or guide polynucleotide from a samplecontaining other polynucleotides.

An oligonucleotide or polynucleotide specifically hybridises to a targetpolynucleotide when it hybridises with preferential or high affinity tothe target polynucleotide but does not substantially hybridise, does nothybridise or hybridises with only low affinity to other polynucleotide.An oligonucleotide or polynucleotide specifically hybridises if ithybridises to the target polynucleotide with a melting temperature(T_(m)) that is at least 2° C., such as at least 3° C., at least 4° C.,at least 5° C., at least 6° C., at least 7° C., at least 8° C., at least9° C. or at least 10° C., greater than its T_(m) for other sequences.More preferably, the oligonucleotide or polynucleotide hybridise to thetarget polynucleotide with a T_(m) that is at least 2° C., such as atleast 3° C., at least 4° C., at least 5° C., at least 6° C., at least 7°C., at least 8° C., at least 9° C., at least 10° C., at least 20° C., atleast 30° C. or at least 40° C., greater than its T_(m) for othernucleic acids. Preferably, the oligonucleotide or polynucleotidehybridises to the target polynucleotide with a T_(m) that is at least 2°C., such as at least 3° C., at least 4° C., at least 5° C., at least 6°C., at least 7° C., at least 8° C., at least 9° C., at least 10° C., atleast 20° C., at least 30° C. or at least 40° C., greater than its T_(m)for a sequence which differs from the target polynucleotide by one ormore nucleotides, such as by 1, 2, 3, 4 or 5 or more nucleotides. Theoligonucleotide or polynucleotide typically hybridises to the targetpolynucleotide with a T_(m) of at least 90° C., such as at least 92° C.or at least 95° C. T_(m) can be measured experimentally using knowntechniques, including the use of DNA microarrays, or can be calculatedusing publicly available T_(m) calculators, such as those available overthe internet.

Conditions that permit the hybridisation are well-known in the art (forexample, Sambrook et al., 2001, Molecular Cloning: a laboratory manual,3rd edition, Cold Spring Harbour Laboratory Press; and Current Protocolsin Molecular Biology, Chapter 2, Ausubel et al., Eds., Greene Publishingand Wiley-lnterscience, New York (1995)). Hybridisation can be carriedout under low stringency conditions, for example in the presence of abuffered solution of 30 to 35% formamide, 1 M NaCl and 1% SDS (sodiumdodecyl sulfate) at 37° C. followed by a 20 wash in from 1× (0.1650 MNa⁺) to 2× (0.33 M Na⁺) SSC (standard sodium citrate) at 50° C.Hybridisation can be carried out under moderate stringency conditions,for example in the presence of a buffer solution of 40 to 45% formamide,1 M NaCl, and 1% SDS at 37° C., followed by a wash in from 0.5×(0.0825 MNa⁺) to 1× (0.1650 M Na⁺) SSC at 55° C. Hybridisation can be carried outunder high stringency conditions, for example in the presence of abuffered solution of 50% formamide, 1 M NaCl, 1% SDS at 37° C., followedby a wash in 0.1×(0.0165 M Na⁺) SSC at 60° C.

The oligonucleotide or polynucleotide may comprise a portion or regionwhich is substantially complementary to a portion or region of thetarget polynucleotide or guide polynucleotide. The region or portion ofthe oligonucleotide or polynucleotide may therefore have 1, 2, 3, 4, 5,6, 7, 8, 9, 10 or more mismatches across a region of 5, 10, 15, 20, 21,22, 30, 40 or 50 nucleotides compared with the portion or region in thetarget polynucleotide or guide polynucleotide.

A portion of region is typically 50 nucleotides or fewer, such as 40nucleotides or fewer, 30 nucleotides or fewer, 20 nucleotides or fewer,10 nucleotides or fewer or 5 nucleotides or fewer.

The microparticle is preferably paramagnetic or magnetic. Themicroparticle preferably comprises a paramagnetic or a superparamagneticmaterial or a paramagnetic or a superparamagnetic metal, such as iron.Any suitable magnetic microparticle may be used. For instance, magneticbeads commercially available from, for instance, Clontech, Promega,Invitrogen ThermoFisher Scientific and NEB, may be used. In someembodiments, the microparticle comprises a magnetic particle with anorganic group such as a metal-chelating group, such as nitrilotriaceticacid (NTA), attached. The organic component may, for instance, comprisea group selected from —C(═O)O—, —C—O—C—, —C(═O)—, —NH—, —C(═O)—NH,—C(═O)—CH₂—I, —S(═O)₂— and —S—. The organic component may comprise ametal chelating group, such as NTA (nitrilotriacetic acid). Usually, ametal such as gold, iron, nickel or cobalt is also attached to themetal-chelating group. Magnetic beads of this sort are commonly used forcapturing His-tagged proteins, but are also suitable for use in theinvention.

The microparticle is most preferably a His-Tag Dynabead® which iscommercially available from Life Technologies, Mag Strep beads from IBA,Streptavidin magnetic beads from NEB, Solid Phase ReversibleImmobilization (SPRI) beads or Agencourt AMPure XP beads from BeckmanCoulter or Dynabeads® MyOne™ Streptavidin Cl (ThermoFisher Scientific).

Membrane

Any membrane may be used in accordance with the invention. Suitablemembranes are well-known in the art. The membrane is preferably anamphiphilic layer or a solid state layer.

An amphiphilic layer is a layer formed from amphiphilic molecules, suchas phospholipids, which have both hydrophilic and lipophilic properties.The amphiphilic molecules may be synthetic or naturally occurring.Non-naturally occurring amphiphiles and amphiphiles which form amonolayer are known in the art and include, for example, blockcopolymers (Gonzalez-Perez et al., Langmuir, 2009, 25, 10447-10450).Block copolymers are polymeric materials in which two or more monomersub-units that are polymerised together to create a single polymerchain. Block copolymers typically have properties that are contributedby each monomer sub-unit. However, a block copolymer may have uniqueproperties that polymers formed from the individual sub-units do notpossess. Block copolymers can be engineered such that one of the monomersub-units is hydrophobic (e.g. lipophilic), whilst the other sub-unit(s)are hydrophilic whilst in aqueous media. In this case, the blockcopolymer may possess amphiphilic properties and may form a structurethat mimics a biological membrane. The block copolymer may be a diblock(consisting of two monomer sub-units), but may also be constructed frommore than two monomer sub-units to form more complex arrangements thatbehave as amphiphiles. The copolymer may be a triblock, tetrablock orpentablock copolymer. The membrane is preferably a triblock copolymermembrane.

Archaebacterial bipolar tetraether lipids are naturally occurring lipidsthat are constructed such that the lipid forms a monolayer membrane.These lipids are generally found in extremophiles that survive in harshbiological environments, thermophiles, halophiles and acidophiles. Theirstability is believed to derive from the fused nature of the finalbilayer. It is straightforward to construct block copolymer materialsthat mimic these biological entities by creating a triblock polymer thathas the general motif hydrophilic-hydrophobic-hydrophilic. This materialmay form monomeric membranes that behave similarly to lipid bilayers andencompass a range of phase behaviours from vesicles through to laminarmembranes. Membranes formed from these triblock copolymers hold severaladvantages over biological lipid membranes. Because the triblockcopolymer is synthesised, the exact construction can be carefullycontrolled to provide the correct chain lengths and properties requiredto form membranes and to interact with pores and other proteins.

Block copolymers may also be constructed from sub-units that are notclassed as lipid sub-materials; for example a hydrophobic polymer may bemade from siloxane or other non-hydrocarbon based monomers. Thehydrophilic sub-section of block copolymer can also possess low proteinbinding properties, which allows the creation of a membrane that ishighly resistant when exposed to raw biological samples. This head groupunit may also be derived from non-classical lipid head-groups.

Triblock copolymer membranes also have increased mechanical andenvironmental stability compared with biological lipid membranes, forexample a much higher operational temperature or pH range. The syntheticnature of the block copolymers provides a platform to customise polymerbased membranes for a wide range of applications.

The membrane is most preferably one of the membranes disclosed inWO2014/064443 or WO2014/064444.

The amphiphilic molecules may be chemically-modified or functionalisedto facilitate coupling of the complex.

The amphiphilic layer may be a monolayer or a bilayer. The amphiphiliclayer is typically planar. The amphiphilic layer may be curved. Theamphiphilic layer may be supported. The amphiphilic layer may beconcave. The amphiphilic layer may be suspended from raised pillars suchthat the peripheral region of the amphiphilic layer (which is attachedto the pillars) is higher than the amphiphilic layer region. This mayallow the microparticle to travel, move, slide or roll along themembrane as described above.

Amphiphilic membranes are typically naturally mobile, essentially actingas two dimensional fluids with lipid diffusion rates of approximately10⁻⁸ cm s−1. This means that the pore and coupled complex can typicallymove within an amphiphilic membrane.

The membrane may be a lipid bilayer. Lipid bilayers are models of cellmembranes and serve as excellent platforms for a range of experimentalstudies. For example, lipid bilayers can be used for in vitroinvestigation of membrane proteins by single-channel recording.Alternatively, lipid bilayers can be used as biosensors to detect thepresence of a range of substances. The lipid bilayer may be any lipidbilayer. Suitable lipid bilayers include, but are not limited to, aplanar lipid bilayer, a supported bilayer or a liposome. The lipidbilayer is preferably a planar lipid bilayer. Suitable lipid bilayersare disclosed in WO 2008/102121, WO 2009/077734 and WO 2006/100484.

Methods for forming lipid bilayers are known in the art. Lipid bilayersare commonly formed by the method of Montal and Mueller (Proc. Natl.Acad. Sci. USA., 1972; 69: 3561-3566), in which a lipid monolayer iscarried on aqueous solution/air interface past either side of anaperture which is perpendicular to that interface. The lipid is normallyadded to the surface of an aqueous electrolyte solution by firstdissolving it in an organic solvent and then allowing a drop of thesolvent to evaporate on the surface of the aqueous solution on eitherside of the aperture. Once the organic solvent has evaporated, thesolution/air interfaces on either side of the aperture are physicallymoved up and down past the aperture until a bilayer is formed. Planarlipid bilayers may be formed across an aperture in a membrane or acrossan opening into a recess.

The method of Montal & Mueller is popular because it is a cost-effectiveand relatively straightforward method of forming good quality lipidbilayers that are suitable for protein pore insertion. Other commonmethods of bilayer formation include tip-dipping, painting bilayers andpatch-clamping of liposome bilayers.

Tip-dipping bilayer formation entails touching the aperture surface (forexample, a pipette tip) onto the surface of a test solution that iscarrying a monolayer of lipid. Again, the lipid monolayer is firstgenerated at the solution/air interface by allowing a drop of lipiddissolved in organic solvent to evaporate at the solution surface. Thebilayer is then formed by the Langmuir-Schaefer process and requiresmechanical automation to move the aperture relative to the solutionsurface.

For painted bilayers, a drop of lipid dissolved in organic solvent isapplied directly to the aperture, which is submerged in an aqueous testsolution. The lipid solution is spread thinly over the aperture using apaintbrush or an equivalent. Thinning of the solvent results information of a lipid bilayer. However, complete removal of the solventfrom the bilayer is difficult and consequently the bilayer formed bythis method is less stable and more prone to noise duringelectrochemical measurement.

Patch-clamping is commonly used in the study of biological cellmembranes. The cell membrane is clamped to the end of a pipette bysuction and a patch of the membrane becomes attached over the aperture.The method has been adapted for producing lipid bilayers by clampingliposomes which then burst to leave a lipid bilayer sealing over theaperture of the pipette. The method requires stable, giant andunilamellar liposomes and the fabrication of small apertures inmaterials having a glass surface.

Liposomes can be formed by sonication, extrusion or the Mozafari method(Colas et al. (2007) Micron 38:841-847).

In a preferred embodiment, the lipid bilayer is formed as described inWO 2009/077734. Advantageously in this method, the lipid bilayer isformed from dried lipids. In a most preferred embodiment, the lipidbilayer is formed across an opening as described in WO2009/077734.

A lipid bilayer is formed from two opposing layers of lipids. The twolayers of lipids are arranged such that their hydrophobic tail groupsface towards each other to form a hydrophobic interior. The hydrophilichead groups of the lipids face outwards towards the aqueous environmenton each side of the bilayer. The bilayer may be present in a number oflipid phases including, but not limited to, the liquid disordered phase(fluid lamellar), liquid ordered phase, solid ordered phase (lamellargel phase, interdigitated gel phase) and planar bilayer crystals(lamellar sub-gel phase, lamellar crystalline phase).

Any lipid composition that forms a lipid bilayer may be used. The lipidcomposition is chosen such that a lipid bilayer having the requiredproperties, such as surface charge, ability to support membraneproteins, packing density or mechanical properties, is formed. The lipidcomposition can comprise one or more different lipids. For instance, thelipid composition can contain up to 100 lipids. The lipid compositionpreferably contains 1 to 10 lipids. The lipid composition may comprisenaturally-occurring lipids and/or artificial lipids.

The lipids typically comprise a head group, an interfacial moiety andtwo hydrophobic tail groups which may be the same or different. Suitablehead groups include, but are not limited to, neutral head groups, suchas diacylglycerides (DG) and ceramides (CM); zwitterionic head groups,such as phosphatidylcholine (PC), phosphatidylethanolamine (PE) andsphingomyelin (SM); negatively charged head groups, such asphosphatidylglycerol (PG); phosphatidylserine (PS), phosphatidylinositol(PI), phosphatic acid (PA) and cardiolipin (CA); and positively chargedheadgroups, such as trimethylammonium-Propane (TAP). Suitableinterfacial moieties include, but are not limited to,naturally-occurring interfacial moieties, such as glycerol-based orceramide-based moieties. Suitable hydrophobic tail groups include, butare not limited to, saturated hydrocarbon chains, such as lauric acid(n-Dodecanolic acid), myristic acid (n-Tetradecononic acid), palmiticacid (n-Hexadecanoic acid), stearic acid (n-Octadecanoic) and arachidic(n-Eicosanoic); unsaturated hydrocarbon chains, such as oleic acid(cis-9-Octadecanoic); and branched hydrocarbon chains, such asphytanoyl. The length of the chain and the position and number of thedouble bonds in the unsaturated hydrocarbon chains can vary. The lengthof the chains and the position and number of the branches, such asmethyl groups, in the branched hydrocarbon chains can vary. Thehydrophobic tail groups can be linked to the interfacial moiety as anether or an ester. The lipids may be mycolic acid.

The lipids can also be chemically-modified. The head group or the tailgroup of the lipids may be chemically-modified. Suitable lipids whosehead groups have been chemically-modified include, but are not limitedto, PEG-modified lipids, such as1,2-Diacyl-sn-Glycero-3-Phosphoethanolamine-N-[Methoxy(Polyethyleneglycol)-2000]; functionalised PEG Lipids, such as1,2-Distearoyl-sn-Glycero-3 Phosphoethanolamine-N-[Biotinyl(PolyethyleneGlycol) 2000]; and lipids modified for conjugation, such as1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine-N-(succinyl) and1,2-Dipalmitoyl-sn-Glycero-3-Phosphoethanolamine-N-(Biotinyl). Suitablelipids whose tail groups have been chemically-modified include, but arenot limited to, polymerisable lipids, such as1,2-bis(10,12-tricosadiynoyl)-sn-Glycero-3-Phosphocholine; fluorinatedlipids, such as1-Palmitoyl-2-(16-Fluoropalmitoyl)-sn-Glycero-3-Phosphocholine;deuterated lipids, such as1,2-Dipalmitoyl-D62-sn-Glycero-3-Phosphocholine; and ether linkedlipids, such as 1,2-Di-O-phytanyl-sn-Glycero-3-Phosphocholine. Thelipids may be chemically-modified or functionalised to facilitatecoupling of the complex.

The amphiphilic layer, for example the lipid composition, typicallycomprises one or more additives that will affect the properties of thelayer. Suitable additives include, but are not limited to, fatty acids,such as palmitic acid, myristic acid and oleic acid; fatty alcohols,such as palmitic alcohol, myristic alcohol and oleic alcohol; sterols,such as cholesterol, ergosterol, lanosterol, sitosterol andstigmasterol; lysophospholipids, such as1-Acyl-2-Hydroxy-sn-Glycero-3-Phosphocholine; and ceramides.

Solid state layers can be formed from both organic and inorganicmaterials including, but not limited to, microelectronic materials,insulating materials such as Si₃N₄, Al₂O₃, and SiO, organic andinorganic polymers such as polyamide, plastics such as Teflon® orelastomers such as two-component addition-cure silicone rubber, andglasses. The solid state layer may be formed from graphene. Suitablegraphene layers are disclosed in WO 2009/035647. Yusko et al., NatureNanotechnology, 2011; 6: 253-260 and US Patent Application No.2013/0048499 describe the delivery of proteins to transmembrane pores insolid state layers without the use of microparticles. The method of theinvention may be used to improve the delivery in the methods disclosedin these documents.

The method is typically carried out using (i) an artificial amphiphiliclayer comprising a pore, (ii) an isolated, naturally-occurring lipidbilayer comprising a pore, or (iii) a cell having a pore insertedtherein. The method is typically carried out using an artificialamphiphilic layer, such as an artificial triblock copolymer layer. Thelayer may comprise other transmembrane and/or intramembrane proteins aswell as other molecules in addition to the pore. Suitable apparatus andconditions are discussed below. The method of the invention is typicallycarried out in vitro.

The membrane to which the complex is delivered is typically contained ina liquid. The liquid keeps the membrane “wet” and stops it drying out.The liquid is typically an aqueous solution. The aqueous solutiontypically has the same density as water. The density of the aqueoussolution is typically about 1 g/cm³. The density of the solution mayvary depending on temperature and the exact composition of the solution.The aqueous solution typically has a density between about 0.97 andabout 1.03 g/cm³.

The membrane typically separates two volumes of aqueous solution. Themembrane resists the flow of electrical current between the volumes. Thetransmembrane pore inserted into the membrane selectively allows thepassage of ions across the membrane, which can be recorded as anelectrical signal detected by electrodes in the two volumes of aqueoussolution. The presence of a complex comprising the target polynucleotidemodulates the flow of ions and is detected by observing the resultantvariations in the electrical signal.

Array

The membrane is typically part of an array of membranes, wherein eachmembrane preferably comprises a transmembrane pore. Therefore, theinvention provides a method of detecting a target polynucleotide usingan array of membranes.

The membrane may be comprised in an apparatus having an array ofelectrically isolated membranes, each individually addressed using itsown electrode, such that the array is equivalent to many individualsensors measuring in parallel from a test sample. The membranes may berelatively densely packed, allowing a large number of membranes to beused for a given volume of test sample. Suitable arrays of membranes andapparatuses are described in the art, for example in WO 2009/077734 andWO2012/042226. WO 2009/077734, for example, discloses a plurality ofindividually addressable lipid bilayers formed across an array ofmicrowell apertures, each microwell containing an electrode and anaqueous medium in contact with the lipid bilayer.

The apparatus is typically provided to the end user in a ‘ready to use’state wherein the membranes and transmembrane pores are pre-inserted. Atypical apparatus provided in a ‘ready to use’ state comprises an arrayof amphiphilic membranes, each membrane comprising a transmembrane poreand being provided across a well containing a liquid. Such an apparatusand method of making it are disclosed by WO2014/064443. Test liquid tobe analysed is applied to the upper surface of the amphiphilicmembranes.

Providing an apparatus in a ‘ready to use’ state however has additionalconsiderations in that care needs to be taken that the sensor does notdry out, namely that liquid is not lost from the well by passage throughthe amphiphilic membrane, which may result in a loss of performance ordamage the sensor. One solution to address the problem of drying out ofthe sensor is to provide the device with a buffer liquid over thesurface of the amphiphilic membrane such that any evaporation throughthe surface of the membrane is minimised and the liquids provided oneither side of the membrane may have the same ionic strength so as toreduce any osmotic effects. In use the buffer liquid may be removed fromthe surface of the amphiphilic membrane and a test liquid to be analysedis introduced to contact the surface.

Some applications may use measurement of electrical properties acrossthe membranes, for example ion current flow. To provide for suchmeasurements, the apparatus may further comprise respective electrodesin each compartment making electrical contact with the volumescomprising polar medium. Other types of measurements may be carried outfor example optical measurements such as fluorescence measurements andFET measurements. Optical measurements and electrical measurements maybe carried out simultaneously (Heron A J et al., J Am Chem Soc. 2009;131(5):1652-3).

The apparatus may further comprise a common electrode. The apparatus mayfurther comprise an electrical circuit connected between the commonelectrode and the respective electrodes in each compartment, theelectrical circuit being arranged to take electrical measurements. Suchelectrical measurements may be dependent on a process occurring at orthrough the membranes.

The apparatus may comprise FET array for making measurements of thenanopore array.

Pore

A nanopore is an aperture with at least one dimension on the nanometrescale. A nanopore may be created by a pore-forming protein or as a holein synthetic materials such as silicon or graphene. Alternatively ananopore may be a hybrid of these e.g., a protein channel set in asynthetic membrane. A nanopore may also be a DNA origami pore or a glasscapillary. A nanopore is typically less than about 20 nm in diameter butcan be up to about 100 nm in diameter.

A transmembrane pore is a structure that crosses a membrane to somedegree. It permits hydrated ions driven by an applied potential to flowacross or within the membrane. The transmembrane pore typically crossesthe entire membrane so that hydrated ions may flow from one side of themembrane to the other side of the membrane. However, the transmembranepore does not have to cross the membrane. It may be closed at one end.For instance, the pore may be a well, gap, channel, trench or slit inthe membrane along which or into which hydrated ions may flow.

Any transmembrane pore may be used in the invention. The pore may bebiological or artificial. Suitable pores include, but are not limitedto, protein pores, polynucleotide pores and solid state pores. The poremay be a DNA origami pore (Langecker et al., Science, 2012; 338:932-936). The transmembrane pore is preferably a transmembrane proteinpore. A transmembrane protein pore is a polypeptide or a collection ofpolypeptides that permits hydrated ions, such as polynucleotide, to flowfrom one side of a membrane to the other side of the membrane. In thepresent invention, the transmembrane protein pore is capable of forminga pore that permits hydrated ions driven by an applied potential to flowfrom one side of the membrane to the other. The transmembrane proteinpore preferably permits polynucleotides to flow from one side of themembrane, such as a triblock copolymer membrane, to the other. Thetransmembrane protein pore allows a polynucleotide, such as DNA or RNA,to be moved through the pore.

The transmembrane protein pore may be a monomer or an oligomer. The poreis preferably made up of several repeating subunits, such as at least 6,at least 7, at least 8, at least 9, at least 10, at least 11, at least12, at least 13, at least 14, at least 15, or at least 16 subunits. Thepore is preferably a hexameric, heptameric, octameric or nonameric pore.The pore may be a homo-oligomer or a hetero-oligomer.

The transmembrane protein pore typically comprises a barrel or channelthrough which the ions may flow. The subunits of the pore typicallysurround a central axis and contribute strands to a transmembrane βbarrel or channel or a transmembrane α-helix bundle or channel.

The barrel or channel of the transmembrane protein pore typicallycomprises amino acids that facilitate interaction with s, such asnucleotides, polynucleotides or nucleic acids. These amino acids arepreferably located near a constriction of the barrel or channel. Thetransmembrane protein pore typically comprises one or more positivelycharged amino acids, such as arginine, lysine or histidine, or aromaticamino acids, such as tyrosine or tryptophan. These amino acids typicallyfacilitate the interaction between the pore and nucleotides,polynucleotides or nucleic acids.

Transmembrane protein pores for use in accordance with the invention canbe derived from β-barrel pores or α-helix bundle pores. β-barrel porescomprise a barrel or channel that is formed from β-strands. Suitableβ-barrel pores include, but are not limited to, β-toxins, such asα-hemolysin, anthrax toxin and leukocidins, and outer membraneproteins/porins of bacteria, such as Mycobacterium smegmatis porin(Msp), for example MspA, MspB, MspC or MspD, CsgG, outer membrane porinF (OmpF), outer membrane porin G (OmpG), outer membrane phospholipase Aand Neisseria autotransporter lipoprotein (NalP) and other pores, suchas lysenin. α-helix bundle pores comprise a barrel or channel that isformed from α-helices. Suitable α-helix bundle pores include, but arenot limited to, inner membrane proteins and a outer membrane proteins,such as WZA and ClyA toxin.

The transmembrane pore may be derived from or based on Msp, α-hemolysin(α-HL), lysenin, CsgG, ClyA, Sp1 and haemolytic protein fragaceatoxin C(FraC). The transmembrane protein pore is preferably derived from CsgG,more preferably from CsgG from E. coli Str. K-12 substr. MC4100.Suitable pores derived from CsgG are disclosed in WO 2016/034591. Thetransmembrane pore may be derived from lysenin. Suitable pores derivedfrom lysenin are disclosed in WO 2013/153359.

The wild type α-hemolysin pore is formed of 7 identical monomers orsub-units (i.e., it is heptameric). The sequence of one monomer orsub-unit of α-hemolysin-NN is disclosed in, for example, WO2016/059375.

The transmembrane protein pore is preferably derived from Msp, morepreferably from MspA. Suitable pores derived from MspA are disclosed inWO 2012/107778.

Any of the proteins described herein, such as the transmembrane proteinpores, may be modified to assist their identification or purification,for example by the addition of histidine residues (a his tag), asparticacid residues (an asp tag), a streptavidin tag, a flag tag, a SUMO tag,a GST tag or a MBP tag, or by the addition of a signal sequence topromote their secretion from a cell where the polypeptide does notnaturally contain such a sequence. An alternative to introducing agenetic tag is to chemically react a tag onto a native or engineeredposition on the pore or construct. An example of this would be to reacta gel-shift reagent to a cysteine engineered on the outside of the pore.This has been demonstrated as a method for separating hemolysinhetero-oligomers (Chem Biol. 1997 July; 4(7):497-505).

The pore may be labelled with a revealing label. The revealing label maybe any suitable label which allows the pore to be detected. Suitablelabels include, but are not limited to, fluorescent molecules,radioisotopes, e.g. ¹²⁵I, ³⁵S, enzymes, antibodies, antigens,polynucleotides and ligands such as biotin.

Any of the proteins described herein, such as the transmembrane proteinpores, may be made synthetically or by recombinant means. For example,the pore may be synthesised by in vitro translation and transcription(IVTT). The amino acid sequence of the pore may be modified to includenon-naturally occurring amino acids or to increase the stability of theprotein. When a protein is produced by synthetic means, such amino acidsmay be introduced during production. The pore may also be alteredfollowing either synthetic or recombinant production.

Any of the proteins described herein, such as the transmembrane proteinpores, can be produced using standard methods known in the art.Polynucleotide sequences encoding a pore or construct may be derived andreplicated using standard methods in the art. Polynucleotide sequencesencoding a pore or construct may be expressed in a bacterial host cellusing standard techniques in the art. The pore may be produced in a cellby in situ expression of the polypeptide from a recombinant expressionvector. The expression vector optionally carries an inducible promoterto control the expression of the polypeptide. These methods aredescribed in Sambrook, J. and Russell, D. (2001). Molecular Cloning: ALaboratory Manual, 3rd Edition. Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y.

The pore may be produced in large scale following purification by anyprotein liquid chromatography system from protein producing organisms orafter recombinant expression. Typical protein liquid chromatographysystems include FPLC, AKTA systems, the Bio-Cad system, the Bio-RadBioLogic system and the Gilson HPLC system.

Diagnosis

The methods of the invention can be used to diagnose or prognose adisease or condition. The disease or condition is preferably cancer,coronary heart disease, cardiovascular disease, tuberculosis or sepsis.

Examples of the disease or condition include abdominal aortic aneurysm,acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), acutemyocardial infarction, acute promyelocytic leukemia (APL), adenoma,adrenocortical carcinoma, alcoholic liver disease, Alzheimer's disease,anaplastic thyroid carcinoma (ATC), anxiety disorder, asthma,astrocytoma, atopic dermatitis, autism spectrum disorder (ASD), B-cellchronic lymphocytic leukemia, B-cell lymphoma, Becker muscular dystrophy(BMD), bladder cancer, brain neoplasm, breast cancer, Burkitt lymphoma,cardiac hypertrophy, cardiomyopathy, cardiovascular disease, cerebellarneurodegeneration, cervical cancer, cholangiocarcinoma, cholesteatoma,choriocarcinoma, chronic lymphocytic leukemia, chronic myeloid leukemia,chronic pancreatitis, colon carcinoma, colorectal cancer, congenitalheart disease, coronary artery disease, cowden syndrome, dermatomyositis(DM), diabetic nephropathy, diarrhea predominant irritable bowelsyndrome, diffuse large B-cell lymphoma, dilated cardiomyopathy, downsyndrome (DS), duchenne muscular dystrophy (DMD), endometrial cancer,endometrial endometrioid adenocarcinoma, endometriosis, epithelialovarian cancer, esophageal cancer, esophagus squamous cell carcinoma,essential thrombocythemia (ET), facioscapulohumeral muscular dystrophy(FSHD), follicular lymphoma (FL), follicular thyroid carcinoma (FTC),frontotemporal dementia, gastric cancer (stomach cancer), glioblastoma,glioblastoma multiforme (GBM), glioma, glomerular disease,glomerulosclerosis, hamartoma, HBV-related cirrhosis, HCV infection,head and neck cancer, head and neck squamous cell carcinoma (HNSCC),hearing loss, heart disease, heart failure, hepatitis B, hepatitis C,hepatocellular carcinoma (HCC), hilar cholangiocarcinoma, Hodgkin'slymphoma, homozygous sickle cell disease (HbSS), Huntington's disease(HD), hypertension, hypopharyngeal cancer, inclusion body myositis(IBM), insulinoma, intrahepatic cholangiocarcinoma (ICC), kidney cancer,kidney disease, laryngeal carcinoma, late insomnia (sleep disease),leiomyoma of lung, leukemia, limb-girdle muscular dystrophies types 2A(LGMD2A), lipoma, lung adenocarcinoma, lung cancer, lymphoproliferativedisease, malignant lymphoma, malignant melanoma, malignant mesothelioma(MM), mantle cell lymphoma (MCL), medulloblastoma, melanoma, meningioma,metabolic disease, miyoshi myopathy (MM), multiple myeloma (MM),multiple sclerosis, MYC-rearranged lymphoma, myelodysplastic syndrome,myeloproliferative disorder, myocardial infarction, myocardial injury,myoma, nasopharyngeal carcinoma (NPC), nemaline myopathy (NM),nephritis, neuroblastoma (NB), neutrophilia, Niemann-Pick type C (NPC)disease, non-alcoholic fatty liver disease (NAFLD), non-small cell lungcancer (NSCLC), obesity, oral carcinomaosteosarcoma ovarian cancer (OC),pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), pancreaticneoplasia, panic disease, papillary thyroid carcinoma (PTC), Parkinson'sdisease, PFV-1 infection, pharyngeal disease, pituitary adenoma,polycystic kidney disease, polycystic liver disease, polycythemia vera(PV), polymyositis (PM), primary biliary cirrhosis (PBC), primarymyelofibrosis, prion disease, prostate cancer, psoriasic arthritis,psoriasis, pulmonary hypertension, recurrent ovarian cancer, renal cellcarcinoma, renal clear cell carcinoma, retinitis pigmentosa (RP),retinoblastoma, rhabdomyosarcoma, rheumatic heart disease and atrialfibrillation, rheumatoid arthritis, sarcoma, schizophrenia, sepsis,serous ovarian cancer, Sezary syndrome, skin disease, small cell lungcancer, spinocerebellar ataxia, squamous carcinoma, T-cell leukemia,teratocarcinoma, testicular germ cell tumor, thalassemia, thyroidcancer, tongue squamous cell carcinoma, tourette's syndrome, type 2diabetes, ulcerative colitis (UC), uterine leiomyoma (ULM), uvealmelanoma, vascular disease, vesicular stomatitis or Waldenstrommacroglobulinemia (WM).

Since in an embodiment using a multiplex method the presence of absenceof two or more target polynucleotides (e.g. at least 5 ore more, 10 ormore, 20 or more or 30 or more) may be determined, it is possible toprognose or diagnose two or more (e.g. 3, 4, 5, 6 or more) of any of thediseases listed above. Accordingly, a multiplex method for detectingand/or analyzing a plurality (e.g. at least 2 or more, at least 3 ormore, at least 10 or more, at least 20 or more or at least 30 or more)of target polynucleotides is provided.

The method may also be used to detect polynucleotides derived from amicroorganism or group of microorganisms. This is useful in diseasediagnosis and monitoring, but also has other applications. For example,the method may be used to analyse gut or vaginal flora, microorganismspresent on the skin or elsewhere. The microorganism may, for example, bea bacterium, virus, fungus or mycobacterium. The method may be used todetermine which infectious agent is causing a disease and hence todetermine the best course of treatment. For example, urinary tractinfections and other infections are increasingly developingantibacterial resistance. The method may be used to determine thebacterium responsible for an infection and hence to identify anantibiotic or other treatment that will successfully treat theinfection.

The method may be used to characterize genomic DNA. In one particularexemplary embodiment, the method may be used to identity polymorphisms,such as SNPs. In another embodiment the method so the invention may beused for repertoire analysis, for example of V(D)J regions. Such methodsmay use samples derived from blood cells, or T-cells for analysis.

The methods may also be used to characterize unknown sequences.

Polynucleotide Binding Protein

The polynucleotide binding protein may be any protein that is capable ofbinding to the polynucleotide and controlling its movement through thepore. It is straightforward in the art to determine whether or not aprotein binds to a polynucleotide. The protein typically interacts withand modifies at least one property of the polynucleotide. The proteinmay modify the polynucleotide by cleaving it to form individualnucleotides or shorter chains of nucleotides, such as di- ortrinucleotides. The moiety may modify the polynucleotide by orienting itor moving it to a specific position, e.g. controlling its movement.

The polynucleotide binding protein is preferably derived from apolynucleotide handling enzyme. A polynucleotide handling enzyme is apolypeptide that is capable of interacting with and modifying at leastone property of a polynucleotide. The enzyme may modify thepolynucleotide by cleaving it to form individual nucleotides or shorterchains of nucleotides, such as di- or trinucleotides. The enzyme maymodify the polynucleotide by orienting it or moving it to a specificposition. The polynucleotide handling enzyme does not need to displayenzymatic activity as long as it is capable of binding thepolynucleotide and controlling its movement through the pore. Forinstance, the enzyme may be modified to remove its enzymatic activity ormay be used under conditions which prevent it from acting as an enzyme.Such conditions are discussed in more detail below.

The polynucleotide handling enzyme is preferably derived from anucleolytic enzyme. The polynucleotide handling enzyme used in theconstruct of the enzyme is more preferably derived from a member of anyof the Enzyme Classification (EC) groups 3.1.11, 3.1.13, 3.1.14, 3.1.15,3.1.16, 3.1.21, 3.1.22, 3.1.25, 3.1.26, 3.1.27, 3.1.30 and 3.1.31. Theenzyme may be any of those disclosed in WO 2010/086603.

Preferred enzymes are polymerases, exonucleases, helicases, translocasesand topoisomerases, such as gyrases. Suitable enzymes include, but arenot limited to, exonuclease I from E. coli, exonuclease III enzyme fromE. coli, RecJ from T. thermophilus and bacteriophage lambda exonuclease,TatD exonuclease and variants thereof. The polymerase may be PyroPhage®3173 DNA Polymerase (which is commercially available from Lucigen®Corporation), SD Polymerase (commercially available from Bioron®) orvariants thereof. The enzyme is preferably Phi29 DNA polymerase or avariant thereof. The topoisomerase is preferably a member of any of theMoiety Classification (EC) groups 5.99.1.2 and 5.99.1.3.

The enzyme is most preferably derived from a helicase. The helicase maybe or be derived from a He1308 helicase, a RecD helicase, such as TraIhelicase or a TrwC helicase, a XPD helicase or a Dda helicase. Thehelicase may be or be derived from He1308 Mbu, He1308 Csy He1308 Tga,He1308 Mhu, TraI Eco, XPD Mbu or a variant thereof.

The helicase may be any of the helicases, modified helicases or helicaseconstructs disclosed in WO 2013/057495, WO 2013/098562, WO2013098561, WO2014/013260, WO 2014/013259, WO 2014/013262 and WO/2015/055981.

The Dda helicase preferably comprises any of the modifications disclosedin WO/2015/055981 and WO 2016/055777.

Any number of helicases may be used in accordance with the invention.For instance, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more helicases may beused. In some embodiments, different numbers of helicases may be used.Any combination of two or more of the helicases mentioned above may beused. The two or more helicases may be two or more Dda helicases. Thetwo or more helicases may be one or more Dda helicases and one or moreTrwC helicases. The two or more helicases may be different variants ofthe same helicase.

The two or more helicases are preferably attached to one another. Thetwo or more helicases are more preferably covalently attached to oneanother. The helicases may be attached in any order and using anymethod. Preferred helicase constructs for use in the invention aredescribed in WO 2014/013260, WO 2014/013259, WO 2014/013262 andWO2015/055981.

Polynucleotide binding ability can be measured using any method known inthe art. For instance, the protein can be contacted with apolynucleotide and its ability to bind to and move along thepolynucleotide can be measured. The protein may include modificationsthat facilitate binding of the polynucleotide and/or facilitate itsactivity at high salt concentrations and/or room temperature. Proteinsmay be modified such that they bind polynucleotides (e.g. retainpolynucleotide binding ability) but do not function as a helicase (e.g.do not move along polynucleotides when provided with all the necessarycomponents to facilitate movement, e.g. ATP and Mg²⁺). Suchmodifications are known in the art. For instance, modification of theMg²⁺ binding domain in helicases typically results in variants which donot function as helicases. These types of variants may act as molecularbrakes.

The enzyme may be covalently attached to the pore. Any method may beused to covalently attach the enzyme to the pore.

In strand sequencing, the polynucleotide is translocated through thepore either with or against an applied potential. Exonucleases that actprogressively or processively on double stranded polynucleotides can beused on the cis side of the pore to feed the remaining single strandthrough under an applied potential or the trans side under a reversepotential. Likewise, a helicase that unwinds the double stranded DNA canalso be used in a similar manner. A polymerase may also be used. Thereare also possibilities for sequencing applications that require strandtranslocation against an applied potential, but the DNA must be first“caught” by the enzyme under a reverse or no potential. With thepotential then switched back following binding the strand will pass cisto trans through the pore and be held in an extended conformation by thecurrent flow. The single strand DNA exonucleases or single strand DNAdependent polymerases can act as molecular motors to pull the recentlytranslocated single strand back through the pore in a controlledstepwise manner, trans to cis, against the applied potential.

Any helicase may be used in the invention. Helicases may work in twomodes with respect to the pore. First, the method is preferably carriedout using a helicase such that it moves the polynucleotide through thepore with the field resulting from the applied voltage. In this mode the5′ end of the polynucleotide is first captured in the pore, and thehelicase moves the polynucleotide into the pore such that it is passedthrough the pore with the field until it finally translocates through tothe trans side of the membrane. Alternatively, the method is preferablycarried out such that a helicase moves the polynucleotide through thepore against the field resulting from the applied voltage. In this modethe 3′ end of the polynucleotide is first captured in the pore, and thehelicase moves the polynucleotide through the pore such that it ispulled out of the pore against the applied field until finally ejectedback to the cis side of the membrane.

The method may also be carried out in the opposite direction. The 3′ endof the polynucleotide may be first captured in the pore and the helicasemay move the polynucleotide into the pore such that it is passed throughthe pore with the field until it finally translocates through to thetrans side of the membrane.

When the helicase is not provided with the necessary components tofacilitate movement or is modified to hinder or prevent its movement, itcan bind to the polynucleotide and act as a brake slowing the movementof the polynucleotide when it is pulled into the pore by the appliedfield. In the inactive mode, it does not matter whether thepolynucleotide is captured either 3′ or 5′ down, it is the applied fieldwhich pulls the polynucleotide into the pore towards the trans side withthe enzyme acting as a brake. When in the inactive mode, the movementcontrol of the polynucleotide by the helicase can be described in anumber of ways including ratcheting, sliding and braking. Helicasevariants which lack helicase activity can also be used in this way.

The polynucleotide may be contacted with the polynucleotide bindingprotein and the pore in any order. It is preferred that, when thepolynucleotide is contacted with the polynucleotide binding protein,such as a helicase, and the pore, the polynucleotide firstly forms acomplex with the protein. When the voltage is applied across the pore,the polynucleotide/protein complex then forms a complex with the poreand controls the movement of the polynucleotide through the pore.

Any steps in the method using a polynucleotide binding protein aretypically carried out in the presence of free nucleotides or freenucleotide analogues and an enzyme cofactor that facilitates the actionof the polynucleotide binding protein. The free nucleotides may be oneor more of any of the individual nucleotides discussed above. The freenucleotides include, but are not limited to, adenosine monophosphate(AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP),guanosine monophosphate (GMP), guanosine diphosphate (GDP), guanosinetriphosphate (GTP), thymidine monophosphate (TMP), thymidine diphosphate(TDP), thymidine triphosphate (TTP), uridine monophosphate (UMP),uridine diphosphate (UDP), uridine triphosphate (UTP), cytidinemonophosphate (CMP), cytidine diphosphate (CDP), cytidine triphosphate(CTP), cyclic adenosine monophosphate (cAMP), cyclic guanosinemonophosphate (cGMP), deoxyadenosine monophosphate (dAMP),deoxyadenosine diphosphate (dADP), deoxyadenosine triphosphate (dATP),deoxyguanosine monophosphate (dGMP), deoxyguanosine diphosphate (dGDP),deoxyguanosine triphosphate (dGTP), deoxythymidine monophosphate (dTMP),deoxythymidine diphosphate (dTDP), deoxythymidine triphosphate (dTTP),deoxyuridine monophosphate (dUMP), deoxyuridine diphosphate (dUDP),deoxyuridine triphosphate (dUTP), deoxycytidine monophosphate (dCMP),deoxycytidine diphosphate (dCDP) and deoxycytidine triphosphate (dCTP).The free nucleotides are preferably selected from AMP, TMP, GMP, CMP,UMP, dAMP, dTMP, dGMP or dCMP. The free nucleotides are preferablyadenosine triphosphate (ATP). The enzyme cofactor is a factor thatallows the construct to function. The enzyme cofactor is preferably adivalent metal cation. The divalent metal cation is preferably Mg²⁺,Mn²⁺, Ca²⁺ or Co²⁺. The enzyme cofactor is most preferably Mg²⁺.

The molecular brakes may be any compound or molecule which binds to thepolynucleotide and slows the movement of the polynucleotide through thepore. The molecular brake may be any of those discussed above. Themolecular brake preferably comprises a compound which binds to thepolynucleotide. The compound is preferably a macrocycle. Suitablemacrocycles include, but are not limited to, cyclodextrins, calixarenes,cyclic peptides, crown ethers, cucurbiturils, pillararenes, derivativesthereof or a combination thereof. The cyclodextrin or derivative thereofmay be any of those disclosed in Eliseev, A. V., and Schneider, H-J.(1994) J Am. Chem. Soc. 116, 6081-6088. The cyclodextrin is morepreferably heptakis-6-amino-β-cyclodextrin (am₇-βCD),6-monodeoxy-6-monoamino-β-cyclodextrin (am₁-βCD) orheptakis-(6-deoxy-6-guanidino)-cyclodextrin (gu₇-βCD).

Polynucleotide Characterisation

The method may involve characterising the target polynucleotide. As thetarget polynucleotide is contacted with the pore, one or moremeasurements which are indicative of one or more characteristics of thetarget polynucleotide are taken as the polynucleotide moves with respectto the pore.

The method may involve measuring two, three, four or five or morecharacteristics of each polynucleotide. The one or more characteristicsare preferably selected from (i) the length of the polynucleotide, (ii)the identity of the polynucleotide, (iii) the sequence of thepolynucleotide, (iv) the secondary structure of the polynucleotide and(v) whether or not the polynucleotide is modified. Any combination of(i) to (v) may be measured in accordance with the invention, such as{i}, {ii}, {iii}, {iv}, {v}, {i,ii}, {i,iii}, {i,iv}, {i,v}, {ii,iii},{ii,iv}, {ii,v}, {iii,iv}, {iii,v}, {iv,v}, {i,ii,iv}, {i,ii,v},{i,iii,iv}, {i,iii,v}, {ii,iii,iv}, {ii,iii,v}, {ii,iv,v}, {iii,iv,v},{i,ii,iii,iv}, {i,ii,iii,v}, {i,ii,iv,v}, {i,iii,iv,v}, {ii,iii,iv,v} or{i,ii,iii,iv,v}.

For (i), the length of the polynucleotide may be measured for example bydetermining the number of interactions between the polynucleotide andthe pore or the duration of interaction between the polynucleotide andthe pore.

For (ii), the identity of the polynucleotide may be measured in a numberof ways. The identity of the polynucleotide may be measured inconjunction with measurement of the sequence of the polynucleotide orwithout measurement of the sequence of the polynucleotide. The former isstraightforward; the polynucleotide is sequenced and thereby identified.The latter may be done in several ways. For instance, the presence of aparticular motif in the polynucleotide may be measured (withoutmeasuring the remaining sequence of the polynucleotide). Alternatively,the measurement of a particular electrical and/or optical signal in themethod may identify the polynucleotide as coming from a particularsource.

For (iii), the sequence of the polynucleotide can be determined asdescribed previously. Suitable sequencing methods, particularly thoseusing electrical measurements, are described in Stoddart D et al., ProcNatl Acad Sci, 12; 106(19):7702-7, Lieberman K R et al, J Am Chem Soc.2010; 132(50):17961-72, and International Application WO 2000/28312.

For (iv), the secondary structure may be measured in a variety of ways.For instance, if the method involves an electrical measurement, thesecondary structure may be measured using a change in dwell time or achange in current flowing through the pore. This allows regions ofsingle-stranded and double-stranded polynucleotide to be distinguished.

For (v), the presence or absence of any modification may be measured.The method preferably comprises determining whether or not thepolynucleotide is modified by methylation, by oxidation, by damage, withone or more proteins or with one or more labels, tags or spacers.Specific modifications will result in specific interactions with thepore which can be measured using the methods described below. Forinstance, methylcyotsine may be distinguished from cytosine on the basisof the current flowing through the pore during its interaction with eachnucleotide.

The methods may be carried out using any apparatus that is suitable forinvestigating a membrane/pore system in which a pore is present in amembrane. The method may be carried out using any apparatus that issuitable for transmembrane pore sensing. For example, the apparatuscomprises a chamber comprising an aqueous solution and a barrier thatseparates the chamber into two sections. The barrier typically has anaperture in which the membrane containing the pore is formed.Alternatively the barrier forms the membrane in which the pore ispresent.

The methods may be carried out using the apparatus described in WO2008/102120).

A variety of different types of measurements may be made. This includeswithout limitation: electrical measurements and optical measurements. Asuitable optical method involving the measurement of fluorescence isdisclosed by J. Am. Chem. Soc. 2009, 131 1652-1653. Possible electricalmeasurements include: current measurements, impedance measurements,tunnelling measurements (Ivanov A P et al., Nano Lett. 2011 Jan. 12;11(1):279-85), and FET measurements (International Application WO2005/124888). Optical measurements may be combined with electricalmeasurements (Soni G V et al., Rev Sci Instrum. 2010 January;81(1):014301). The measurement may be a transmembrane currentmeasurement such as measurement of ionic current flowing through thepore.

Electrical measurements may be made using standard single channelrecording equipment as describe in Stoddart D et al., Proc Natl AcadSci, 12; 106(19):7702-7, Lieberman K R et al, J Am Chem Soc. 2010;132(50):17961-72, and International Application WO 2000/28312.Alternatively, electrical measurements may be made using a multi-channelsystem, for example as described in International Application WO2009/077734 and International Application WO 2011/067559.

The method is preferably carried out with a potential applied across themembrane. The applied potential may be a voltage potential.Alternatively, the applied potential may be a chemical potential. Anexample of this is using a salt gradient across a membrane, such as anamphiphilic layer. A salt gradient is disclosed in Holden et al., J AmChem Soc. 2007 Jul. 11; 129(27):8650-5. In some instances, the currentpassing through the pore as a polynucleotide moves with respect to thepore is used to estimate or determine the sequence of thepolynucleotide. This is strand sequencing.

The methods may involve measuring the current passing through the poreas the polynucleotide moves with respect to the pore. Therefore theapparatus may also comprise an electrical circuit capable of applying apotential and measuring an electrical signal across the membrane andpore. The methods may be carried out using a patch clamp or a voltageclamp. The methods preferably involve the use of a voltage clamp.

The methods may involve the measuring of a current passing through thepore as the polynucleotide moves with respect to the pore. Suitableconditions for measuring ionic currents through transmembrane proteinpores are known in the art and disclosed in the Example. The method istypically carried out with a voltage applied across the membrane andpore. The voltage used is typically from +5 V to −5 V, such as from +4 Vto −4 V, +3 V to −3 V or +2 V to −2 V. The voltage used is typicallyfrom −600 mV to +600 mV or −400 mV to +400 mV. The voltage used ispreferably in a range having a lower limit selected from −400 mV, −300mV, −200 mV, −150 mV, −100 mV, −50 mV, −20 mV and 0 mV and an upperlimit independently selected from +10 mV, +20 mV, +50 mV, +100 mV, +150mV, +200 mV, +300 mV and +400 mV. The voltage used is more preferably inthe range 100 mV to 240 mV and most preferably in the range of 120 mV to220 mV. It is possible to increase discrimination between differentnucleotides by a pore by using an increased applied potential.

The methods are typically carried out in the presence of any chargecarriers, such as metal salts, for example alkali metal salt, halidesalts, for example chloride salts, such as alkali metal chloride salt.Charge carriers may include ionic liquids or organic salts, for exampletetramethyl ammonium chloride, trimethylphenyl ammonium chloride,phenyltrimethyl ammonium chloride, or 1-ethyl-3-methyl imidazoliumchloride. In the exemplary apparatus discussed above, the salt ispresent in the aqueous solution in the chamber. Potassium chloride(KCl), sodium chloride (NaCl), caesium chloride (CsCl) or a mixture ofpotassium ferrocyanide and potassium ferricyanide is typically used.KCl, NaCl and a mixture of potassium ferrocyanide and potassiumferricyanide are preferred. The charge carriers may be asymmetric acrossthe membrane. For instance, the type and/or concentration of the chargecarriers may be different on each side of the membrane.

The salt concentration may be at saturation. The salt concentration maybe 3 M or lower and is typically from 0.1 to 2.5 M, from 0.3 to 1.9 M,from 0.5 to 1.8 M, from 0.7 to 1.7 M, from 0.9 to 1.6 M or from 1 M to1.4 M. The salt concentration is preferably from 150 mM to 1 M. Themethod is preferably carried out using a salt concentration of at least0.3 M, such as at least 0.4 M, at least 0.5 M, at least 0.6 M, at least0.8 M, at least 1.0 M, at least 1.5 M, at least 2.0 M, at least 2.5 M orat least 3.0 M. High salt concentrations provide a high signal to noiseratio and allow for currents indicative of the presence of a nucleotideto be identified against the background of normal current fluctuations.

The methods are typically carried out in the presence of a buffer. Inthe exemplary apparatus discussed above, the buffer is present in theaqueous solution in the chamber. Any buffer may be used in the method ofthe invention. Typically, the buffer is phosphate buffer. Other suitablebuffers are HEPES and Tris-HCl buffer. The methods are typically carriedout at a pH of from 4.0 to 12.0, from 4.5 to 10.0, from 5.0 to 9.0, from5.5 to 8.8, from 6.0 to 8.7 or from 7.0 to 8.8 or 7.5 to 8.5. The pHused is preferably about 7.5.

The methods may be carried out at from 0° C. to 100° C., from 15° C. to95° C., from 16° C. to 90° C., from 17° C. to 85° C., from 18° C. to 80°C., 19° C. to 70° C., or from 20° C. to 60° C. The methods are typicallycarried out at room temperature. The methods are optionally carried outat a temperature that supports enzyme function, such as about 37° C.

Free Nucleotides and Co-Factors

The method may be carried out in the presence of free nucleotides orfree nucleotide analogues and/or an enzyme cofactor that facilitates theaction of the polynucleotide binding protein. The method may also becarried out in the absence of free nucleotides or free nucleotideanalogues and in the absence of an enzyme cofactor. The free nucleotidesmay be one or more of any of the individual nucleotides discussed above.The free nucleotides include, but are not limited to, adenosinemonophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate(ATP), guanosine monophosphate (GMP), guanosine diphosphate (GDP),guanosine triphosphate (GTP), thymidine monophosphate (TMP), thymidinediphosphate (TDP), thymidine triphosphate (TTP), uridine monophosphate(UMP), uridine diphosphate (UDP), uridine triphosphate (UTP), cytidinemonophosphate (CMP), cytidine diphosphate (CDP), cytidine triphosphate(CTP), cyclic adenosine monophosphate (cAMP), cyclic guanosinemonophosphate (cGMP), deoxyadenosine monophosphate (dAMP),deoxyadenosine diphosphate (dADP), deoxyadenosine triphosphate (dATP),deoxyguanosine monophosphate (dGMP), deoxyguanosine diphosphate (dGDP),deoxyguanosine triphosphate (dGTP), deoxythymidine monophosphate (dTMP),deoxythymidine diphosphate (dTDP), deoxythymidine triphosphate (dTTP),deoxyuridine monophosphate (dUMP), deoxyuridine diphosphate (dUDP),deoxyuridine triphosphate (dUTP), deoxycytidine monophosphate (dCMP),deoxycytidine diphosphate (dCDP) and deoxycytidine triphosphate (dCTP).The free nucleotides are preferably selected from AMP, TMP, GMP, CMP,UMP, dAMP, dTMP, dGMP or dCMP. The free nucleotides are preferablyadenosine triphosphate (ATP). The enzyme cofactor is a factor thatallows the polynucleotide binding protein to function. The enzymecofactor is preferably a divalent metal cation. The divalent metalcation is preferably Mg²⁺, Mn²⁺, Ca²⁺ or Co²⁺. The enzyme cofactor ismost preferably Mg²⁺.

Measurement Types

A variety of different types of measurements may be made. This includeswithout limitation: electrical measurements and optical measurements. Asuitable optical method involving the measurement of fluorescence isdisclosed by J. Am. Chem. Soc. 2009, 131 1652-1653. Possible electricalmeasurements include: current measurements, impedance measurements,tunnelling measurements (Ivanov A P et al., Nano Lett. 2011 Jan. 12;11(1):279-85), and FET measurements (International Application WO2005/124888). Optical measurements may be combined with electricalmeasurements (Soni G V et al., Rev Sci Instrum. 2010 January;81(1):014301). The measurement may be a transmembrane currentmeasurement such as measurement of ionic current flowing through thepore. Electrical measurements may be made using standard single channelrecording equipment as describe in Stoddart D et al., Proc Natl AcadSci, 12; 106(19):7702-7, Lieberman K R et al, J Am Chem Soc. 2010;132(50):17961-72, and International Application WO 2000/28312.Alternatively, electrical measurements may be made using a multi-channelsystem, for example as described in International Application WO2009/077734 and International Application WO 2011/067559.

The method is preferably carried out with a potential applied across themembrane. The applied potential may be a voltage potential.Alternatively, the applied potential may be a chemical potential. Anexample of this is using a salt gradient across a membrane, such as anamphiphilic layer. A salt gradient is disclosed in Holden et al., J AmChem Soc. 2007 Jul. 11; 129(27):8650-5. In some instances, the currentpassing through the pore as a polynucleotide moves with respect to thepore is used to estimate or determine the sequence of thepolynucleotide. This is strand sequencing.

Kits

The invention also provides a kit for use in a method of the invention.The kit typically comprises: a polynucleotide-guided effector proteinand an anchor capable of coupling to a membrane. The kit may furthercomprise one or more of a guide polynucleotide, an adaptor sequence, apolynucleotide binding protein capable of moving along a polynucleotideand/or a leader sequence. The kit may further comprise a microparticle.

The guide polynucleotide, polynucleotide-guided effector protein,anchor, adaptor, polynucleotide binding protein, leader sequence and/ormicroparticle may be any of those defined herein. The kit may comprise apanel of guide polynucleotides or of guidepolynucleotide/polynucleotide-guided effector protein complexes. Thepanel is typically designed for a particular purpose, such as to detecta particular microorganism, markers associated with a disease,particular polymorphisms etc.

The kit may comprise components of any of the membranes disclosed above,such as an amphiphilic layer or a triblock copolymer membrane. The kitmay further comprise a transmembrane pore. Any of the embodimentsdiscussed above with reference to the method equally apply to the kits.

The kit may additionally comprise one or more other reagents orinstruments which enable any of the embodiments mentioned above to becarried out. Such reagents or instruments include one or more of thefollowing: suitable buffer(s) (aqueous solutions), means to obtain asample from a subject (such as a vessel or an instrument comprising aneedle), means to amplify and/or express polynucleotides, a membrane asdefined above or voltage or patch clamp apparatus. Reagents may bepresent in the kit in a dry state such that a fluid sample is used toresuspend the reagents. The kit may also, optionally, compriseinstructions to enable the kit to be used in the methods describedherein or details regarding for which organism the method may be used.The kit may comprise a magnet or an electromagnet. The kit may,optionally, comprise nucleotides.

The kit may comprise a guide polynucleotide having an end extension, orfirst and second end extensions as described herein and a captureoligonucleotide or first and second capture oligonucleotides asdescribed herein. The kit may further comprise a competitoroligonucleotide as described herein. The kit may further comprise beadscomprising one half of an affinity molecule pair (e.g. streptavidin) andfirst and second capture oligonucleotides comprising the other half ofan affinity molecule pair (e.g. biotin). The first and second captureoligonucleotides may each be bound to a separate surface, e.g. to aseparate population of beads. The first capture oligonucleotide may bebound, for example, to “purification” beads or to a “purification”column. The second capture oligonucleotide may be bound, for example, to“delivery” beads. The “purification” beads and/or the “delivery” beadsmay be magnetic.

Also provided is a system for detecting a target polynucleotide in asample comprising: a nanopore; a polynucleotide-guided effector proteincomprising a guide polynucleotide binding domain; and a guidepolynucleotide comprising a first portion that is complementary to asequence in a portion of the target polynucleotide and a structure thatis adapted to bind to the guide polynucleotide binding domain of thepolynucleotide-guided effector protein. In one embodiment, the systemfurther comprises a membrane, wherein the nanopore is present in themembrane. In one embodiment, the system further comprises a targetpolynucleotide. In one embodiment of the system, the targetpolynucleotide, guide polynucleotide and polynucleotide-guided effectorprotein form a complex. In one embodiment of the system, the targetpolynucleotide is coupled to a membrane.

The following non-limiting Examples illustrate the invention.

Example 1

This Example describes a method for detection of a specific targetpolynucleotide in a mixture by a nanopore. In this Example, the targetDNA is identified using two types of CRISPR-Cas probes that bind to atarget polynucleotide. The first contains an extension that anchors thetarget polynucleotide to the membrane via a cholesterol-taggedCRISPR-Cas probe. The second (“the analyte”) bears an extension carryinga bound polynucleotide binding protein (helicase), and positivelyidentifies the target polynucleotide indirectly via polynucleotidebinding protein controlled movement of a barcode sequence on the analytethrough a nanopore.

Materials and Methods

Oligonucleotides AR131 and AR132 were annealed, each at 40 μM, in 10 mMTris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl, from 95° C. to 25° C. at 0.6°C. per minute. The hybridised DNA was known as “cholesterol hyb”(ONLA17351).

Oligonucleotides AR130 and ONLA11326 were annealed, each at 40 μM, in 10mM Tris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl, from 95° C. to 25° C. at0.6° C. per minute. The hybridised DNA was known as ONLA17350. Thepolynucleotide binding protein was loaded and closed on thestall-containing strand of ONLA17350 as follows: the helicase wasbuffer-exchanged into 50 mM HEPES (pH 8.0), 100 mM potassium acetate, 1mM EDTA using a Zeba desalting column (Thermo); the helicase was loadedon ONLA17350 by incubation (200 μl) of 500 nM (molecules) ONLA17350 witha 3.5 μM buffer-exchanged helicase in 50 mM HEPES (pH 8.0), 100 mMpotassium acetate at room temperature for 5 min. The helicase was thenclosed around DNA by incubation of the mixture with 100 μM TMAD for 1 hat room temperature (final volume, 220 μl). Non-specifically bound andunclosed helicase was run off the adaptor using 0.25-volume equivalentof a salt-ATP stress buffer (55 μl) comprising 5 mM ATP, 10 mM MgCl₂,2.5 M NaCl, 100 mM Tris (pH 8.0) (final volume, 275 μl), for 25 min atroom temperature. The complex was subjected to SPRI purification byaddition of 3.7-volume equivalents of SPRI beads in 25 mM Tris-Cl (pH7.5 at 21° C.), 28% (w/v) PEG-8000, 2.5 M NaCl for 5 min at roomtemperature. The beads were pelleted on a magnetic rack and thesupernatant removed. While still on the magnetic rack the beads werewashed with 500 ul of 50 mM Tris (pH 7.5 at 21° C.), 2.5 M NaCl, 20% PEG(w/v) 8,000, turning through 360° to bathe the pellet on the rack. Thewash buffer was removed and the pellet pulsed briefly in a centrifugebefore returning to the magnetic rack to remove the last remnants ofsolution. The pellet was then resuspended in 30 ul of 25 mM Tris-Cl (pH7.5 at 21° C.), 20 mM NaCl for 5 mins at room temperature before beingplaced on a magnetic rack to recover the purified adapter which wasknown as “helicase-Y-adaptor hyb”.

A 3.6-kilobase test analyte was amplified by PCR using specific primersdirected against lambda phage genomic DNA, resulting in adouble-stranded DNA analyte bearing blunt ends. This analyte was knownas “blunt lambda 3.6 kb”. CRISPR RNAs (“crRNAs”) bearing 3′ extensionsthat allow hybridisation to either “cholesterol hyb” or“helicase-Y-adaptor hyb” were hybridised with tracrRNA by annealing 40μM “Alt-R™” tracrRNA (purchased from IDT) with each crRNA separately in10 mM Tris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl from 65° C. to 25° C. at1.0° C. per minute, resulting in complex known as a “guide RNA”.CRISPR-dCas9 complexes were formed by incubating 100 nM “guide RNA” with100 nM dCas9 (ONLP11836) in Cas9 binding buffer (20 mM HEPES-NaOH, 100mM NaCl, 5 mM MgCl₂, 0.1 mM EDTA, pH 6.5 at 25° C.), for 10 minutes at21° C., yielding 100 nM of CRISPR-dCas9 complex. These complexes, withbound dCas9, were known as “anchor probes” or “helicase probes”,according to whether “cholesterol hyb” or “helicase-Y-adaptor hyb” cananneal to the crRNA 3′ extension, respectively.

In this example, the “anchor probes” comprised oligonucleotide AR145 orAR138 or AR141 or AR142, hybridised separately to tracrRNA, with bounddCas9, at a molecular concentration of 100 nM of each named species.

In this Example, the “helicase probes” comprised 100 nM oligonucleotidesAR133 or AR134 or AR135, hybridised separately to tracrRNA, with bounddCas9, at a molecular concentration of 100 nM of each named species.

The “anchor probes” and “helicase probes” were pooled together in thefollowing combinations, to a total of 20 μl, according to the tablebelow:

“Probe “Helicase combination” “Anchor probes” probes” A AR145 AR133 BNone (control) AR133 C AR145 None (control) D AR138, AR141, AR142 AR134,AR135 E None (control) None (control)

These mixtures were known as “probe combinations”.

To 20 μl of “probe combinations” (100 nM molecules) was added 1.1 μl oftarget DNA (“blunt 3.6 kb, ONLA17510”) to a final concentration of 10 nMmolecules of ONLA17510, resulting in a complex known as “probe-targetcomplex”. 21.1 μL of “probe-target complex” was diluted to a finalvolume of 100 μL in a mixture of “helicase-Y-adaptor hyb”, “cholesterolhyb”, HEPES-KOH, KCl, MgCl₂ and rATP, resulting in final concentrationsof 25 mM HEPES-KOH, 500 mM KCl, 10 mM MgCl₂, 10 mM rATP, 30 nM“helicase-Y-adaptor hyb”, 100 nM “cholesterol hyb”, 10 nM “CRISPR-dCas9complex”, pH 8.0, known as “MinION reaction mix”. The “MinION reactionmix” was incubated for 10 min at ambient temperature before subjectingthe mixture to nanopore analysis, as follows: Electrical measurementswere acquired from single CsgG nanopores inserted in block co-polymer inbuffer at 37° C. (25 mM HEPES-KOH, 150 mM potassium ferrocyanide (II),150 mM potassium ferricyanide (III), pH 8.0). After achieving a singlepore inserted in the block co-polymer, buffer (2 mL, 25 mM HEPES-KOH,150 mM potassium ferrocyanide (II), 150 mM potassium ferricyanide (III),pH 8.0) was flowed through the system to remove any excess CsgGnanopores. All subsequent steps were performed at 34° C. The ciscompartment was equilibrated with 500 μl of 25 mM HEPES-KOH (pH 8.0),500 mM KCl, 10 mM MgCl₂ and 10 mM rATP (known as “wash buffer”), with 10mins between each wash. 75 μl of “MinION reaction mix”, pre-incubatedfor 10 min at 21° C., was applied to the flow-cell and incubated for 10min to allow any probe-dCas9 complexes contacting target DNA to attachto the block co-polymer. After a further 10 min, a further 2 mL of “washbuffer” was perfused through the flow-cell to remove any non-specifictarget DNA, including any dCas9-bound CRISPR probes and“helicase-Y-adaptor hybs” not contacting the target. The experiment wasrun at 180 mV and helicase-controlled DNA movement monitored. Theelectrical signals resulting from the translocation of DNA strands wereanalysed by counting the frequency of nanopore of the helicase-Y-adaptorhyb, identified by its distinctive electrical current signal.

Results

The helicase was used to control the movement of Cas-contactedpre-sequencing mix, tethered to tri-block copolymer via “cholesterolhyb”, through an CsgG nanopore. FIG. 8 shows a target DNA moleculebearing two CRISPR-dCas9 probes bound to their cognate sites in thetarget DNA. FIG. 23 shows the electrical signal resulting fromhelicase-controlled translocation of the analyte through the nanopore.The example signals show that both the “anchor probes” and the “helicaseprobes” contacted the target DNA. The data demonstrate thatimmobilisation of the target polynucleotide via a tethered CRISPR-dCas9complex successfully identified the target DNA polynucleotide.

Example 2

This Example describes a method for direct enrichment and sequencing ofa fragment containing a specific 20 nt target DNA polynucleotidesequence (“target”) from a mixture by nanopore sequencing, wherein thetarget DNA contacts a cholesterol-tagged CRISPR-Cas probe and movementof DNA through the nanopore is controlled by a DNA motor protein. Inthis example, the “target” is positively identified directly by itssequence. The bound CRISPR-Cas probe may temporarily stall thetranslocation of the helicase and may thus also be used to additionallypositively identify the sample.

Materials and Methods

Oligonucleotides AR131 and AR132 were annealed, each at 40 μM, in 10 mMTris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl, from 95° C. to 25° C. at 0.6°C. per minute. The hybridised DNA was known as “cholesterol hyb”(ONLA17351).

CRISPR RNAs (“crRNAs”) bearing 3′ extensions that allow hybridisation toa “cholesterol hyb” were hybridised with tracrRNA by annealing 40 μM“Alt-R™” tracrRNA (purchased from IDT) with oligonucleotide AR139 in 10mM Tris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl from 65° C. to 25° C. at1.0° C. per minute, resulting in a complex known as a “guide RNA”.CRISPR-dCas9 complexes were formed by incubating 100 nM “guide RNA” with100 nM dCas9 (ONLP11836) in Cas9 binding buffer (20 mM HEPES-NaOH, 100mM NaCl, 5 mM MgCl₂, 0.1 mM EDTA, pH 6.5 at 25° C.), for 10 minutes at21° C., yielding 100 nM of CRISPR-dCas9 complex. These complexes, withbound dCas9, were known as “anchor probes” because “cholesterol hyb”could anneal to the crRNA 3′ extension. Enterobacteria lambda phagegenomic DNA was fragmented to an average size of approximately 1 kbusing a gTube (Covaris, Inc.). The fragmented DNA was end-repaired anddA-tailed using an NEBNext End-Repair/dA-tailing Module (NEB). StandardSK007 adapter was ligated to end-repaired, fragmented lambda phage DNApurified using SPRI beads. To the resultant library (25 μl; 1 μg totalDNA) was added 275 nM (molecules) of ONLA16941 at room temperaturefor >5 minutes to block the leader against non-specific hybridisation of“cholesterol hyb”. The resultant DNA library, bearing end-ligated,loaded helicase on both DNA ends, was known as “pre-sequencing mix”.

To 12 μl pre-sequencing mix was added 33 μl “anchor probe”, yielding amixture containing 73 nM “anchor probe” and approx. 0.32 nM targetsites. The binding was allowed to proceed for 10 min at 21° C., afterwhich the mixture was subjected to purification step using SPRI magneticbeads, as follows: 0.4 volume equivalents of AMPure XP SPRI magneticbeads (Beckman Coulter) were added to the mixture and the resultantmixture agitated for 5 min at 21° C. The magnetic beads were pelletedusing a magnetic separator, the supernatant aspirated, and 100 μl of 50mM Tris-Cl, 2.5 M NaCl, 20% PEG 8,000 (pH 7.5 at 25° C.) added to thebeads while still on the rack, turning the pellet through 360° to washthe pellet on the rack. The beads were immediately pelleted once moreand the supernatant aspirated, after which the tube was removed from therack and 45 μl of a buffer containing of 25 mM Tris-Cl, 20 mM NaCl (pH7.5 at 25° C.) added to the beads to elute the DNA by incubation for 5min at 21° C. The beads were pelleted using the magnetic separator, andthe eluate retained (known as “probe-target complex”).

45 μL of “probe-target complex” was diluted to a final volume of 330 μLin a mixture of ONLA17351, HEPES-KOH, KCl, MgCl₂ and rATP, resulting infinal concentrations of 25 mM HEPES-KOH, 500 mM KCl, 10 mM MgCl₂, 10 mMrATP, 10 nM ONLA17351, 10 nM “CRISPR-dCas9 complex” and approx. 44 pMtarget sites, pH 8.0, known as “MinION reaction mix”.

Electrical measurements were acquired from single CsgG nanoporesinserted in block co-polymer in buffer at 37° C. (25 mM HEPES-KOH, 150mM potassium ferrocyanide (II), 150 mM potassium ferricyanide (III), pH8.0). After achieving a single pore inserted in the block co-polymer,buffer (2 mL, 25 mM HEPES-KOH, 150 mM potassium ferrocyanide (II), 150mM potassium ferricyanide (III), pH 8.0) was flowed through the systemto remove any excess CsgG nanopores. All subsequent steps were performedat 34° C. The cis compartment was equilibrated with 500 μl of 25 mMHEPES-KOH (pH 8.0), 500 mM KCl, 10 mM MgCl₂ and 10 mM rATP (known as“wash buffer”), with 10 mins between each wash. 150 μl of “MinIONreaction mix”, pre-incubated for 10 min at 21° C., was applied to theflow-cell and incubated for 10 min to allow any cholesterol:CRISPRprobe:dCas9 complexes contacting target DNA to attach to the blockco-polymer. After a further 10 min, a further 2 mL of “wash buffer” wasperfused through the flow-cell to remove any non-specific target DNA.The experiment was run at 180 mV and helicase-controlled DNA movementmonitored. The electrical signals resulting from the translocation ofDNA strands were analysed and their nucleotide sequences determined.

Results

The helicase was used to control the movement of Cas-contactedpre-sequencing mix, tethered to tri-block copolymer via “cholesterolhyb”, through an CsgG nanopore. FIG. 9 shows a target DNA moleculebearing an end-loaded helicase, CRISPR-dCas9 bound to its cognate siteand the cholesterol tether. FIG. 15 shows the path of the helicase andhow its translocation might be transiently stalled upon encounter of thebound CRISPR-dCas9 complex. FIG. 22 shows the electrical signalresulting from helicase-controlled translocation of target DNA (in thiscase, a 3.6-kilobase fragment of lambda DNA) through the nanopore andone such transient stalling event, mid-way through the translocationevent. The example signal shows that dCas9 contacted the target DNA, andthat the helicase contacted the dCas9. The data demonstrate thatimmobilisation of the target polynucleotide via a tethered CRISPR-dCas9complex successfully enriched (see FIG. 21) and sequenced the target DNApolynucleotide in preference to the other non-specific fragments.

Example 3

This Example describes a method for direct enrichment and sequencing ofa fragment containing a specific 20 nt target DNA polynucleotidesequence (“target”) from a mixture of DNA polynucleotides (“DNA”) bynanopore sequencing, wherein the target DNA contacts acholesterol-tagged CRISPR-Cas probe. In this Example, the mixture ofoligonucleotides bear an polynucleotide binding protein loaded on aY-adaptor at each end of the mixture of DNA. In this example, Y-adaptordoes not contain a stall site, but is anchored to a membrane surface viaa tether oligonucleotide containing a cholesterol moiety hybridised tothe Y-adaptor. The motor protein fully unwinds any DNA in the mixturethat does not contain a bound CRISPR-Cas complex, thereby releasingnon-target DNA from the membrane. Additionally, an exonuclease, such asE. coli Exonuclease I, may be used to degrade the non-translocatedstrand of the target concomitantly with DNA motor translocation, as wellas any non-target DNA in the sample that is fully unwound. Thepolynucleotide binding protein partially unwinds any DNA that contains abound CRISPR-Cas complex, but stalls upon encounter of the CRISPR-Cascomplex independent of the nanopore. Upon capture of the target by thenanopore, the CRISPR-Cas complex is dislodged from the target by theapplied potential, thereby resuming the translocation of thepolynucleotide binding protein on the target. The sequence of theanalyte and the position of the stall may be used to positively identifythe sample.

Methods

Oligonucleotides AR131 and AR132 were annealed, each at 40 μM, in 10 mMTris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl, from 95° C. to 25° C. at 0.6°C. per minute. The hybridised DNA was known as “cholesterol hyb”(ONLA17351).

CRISPR RNAs (“crRNAs”) bearing 3′ extensions that allow hybridisation toa “cholesterol hyb” were hybridised with tracrRNA by annealing 40 μM“Alt-R™” tracrRNA (purchased from IDT) with oligonucleotide AR145 in 10mM Tris-Cl (pH 8.0), 1 mM EDTA, 100 mM NaCl from 65° C. to 25° C. at1.0° C. per minute, resulting in a complex known as a “guide RNA”.CRISPR-dCas9 complexes were formed by incubating 100 nM “guide RNA” with100 nM dCas9 (ONLP11836) in Cas9 binding buffer (20 mM HEPES-NaOH, 100mM NaCl, 5 mM MgCl₂, 0.1 mM EDTA, pH 6.5 at 25° C.), for 10 minutes at21° C., yielding 100 nM of CRISPR-dCas9 complex. These complexes, withbound dCas9, were known as “anchor probes” because “cholesterol hyb”could anneal to the crRNA 3′ extension.

Approx. 20 nM of Y-adapter ONLA17917, bearing the helicase, was ligatedto 1 μg of end-repaired, dA-tailed 3.6 kb DNA CS (ONLA1751.0) using20,000 units of NEB Quick T4 DNA ligase in 66 mM Tris-C1 (pH 8.0), 10MgCl₂, 2 mM ATPγS, 4.5% (w/v) PEG-8000 in a volume of 100 μl at ambienttemperature for 10 min. The ligated DNA was purified by SPRIpurification as detailed in Example 2, except the DNA was eluted in 24of 20 mM CAPS, 40 mM KCl (pH 10). To this DNA was added 10 nM(molecules) of “anchor probes”, and the sample incubated for 10 min atambient temperature to allow the anchor probes to contact the target. Tothis DNA was added 10 nM (molecules) of SK43, an oligonucleotide bearinga cholesterol moiety that can hybridise to the Y-adaptor. This yielded a3.6-kilobase target double-stranded DNA bearing an polynucleotidebinding protein loaded Y-adaptor on each end, known as “MinIONsequencing mix”.

Pre-sequencing mix was diluted to a volume of 150 μl for analysisresulting in a mixture containing: 25 mM HEPES-KOH (pH 8.0), 500 mM KCl,10 nM cholesterol hyb (ONLA17351), and approx. 250 ng of MinIONsequencing mix.

Electrical measurements were acquired from single CsgG nanoporesinserted in block co-polymer in buffer at 37° C. (25 mM HEPES-KOH, 150mM potassium ferrocyanide (II), 150 mM potassium ferricyanide (III), pH8.0). After achieving a single pore inserted in the block co-polymer,buffer (2 mL, 25 mM HEPES-KOH, 150 mM potassium ferrocyanide (II), 150mM potassium ferricyanide (III), pH 8.0) was flowed through the systemto remove any excess CsgG nanopores. All subsequent steps were performedat 34° C. The cis compartment was equilibrated twice with 500 μl of 25mM HEPES-KOH (pH 8.0), 500 mM KCl (known as “fuel-less wash buffer”),with 10 mins between each wash. 150 μl of “MinION reaction mix”,pre-incubated for 10 min at 21° C., was applied to the flow-cell andincubated for 10 min to allow any cholesterol:CRISPR probe:dCas9complexes contacting target DNA to attach to the block co-polymer. Aftera further 10 min, a further 2 mL of “fuel-less wash buffer” was perfusedthrough the flow-cell to remove any unbound target DNA. The experimentwas run at 180 mV and nanopore currents monitored for approx. 800 s,after which the flow-cell was perfused with 2 mL of 25 mM HEPES-KOH (pH8.0), 500 mM KCl, 10 mM ATP, 0.1 mM MgCl₂. The electrical signalsresulting from the translocation of DNA strands were analysed and theirnucleotide sequences determined.

Results

The helicase was ligated on both ends of the target in the presence ofnon-hydrolysable ATP analogue ATPγS, and used to unwind any target DNAthat did not contain a bound CRISPR-dCas9, or which preceded theCRISPR-dCas9 stall, independent of a nanopore. CRISPR-dCas9 and ligatedY-adaptor were tethered to tri-block copolymer via “cholesterol hyb” andvia an oligonucleotide hybridized to both ends of the target. FIG. 28shows the immobilization of the target to a membrane surface. The targetbears a bound CRISPR-dCas9 probe, and, in the absence of MgATP, thehelicase is located at the ends of the target DNA. FIG. 29 shows thetranslocation and stalling of both helicases towards the boundCRISPR-dCas9 complex upon the addition of MgATP. The stalling may beaccomplished by one or both helicases. FIG. 30 shows the capture of thetarget analyte by a nanopore upon application of potential. FIG. 31shows dislodgement of the bound CRISPR-dCas9 complex by the helicaseupon capture of the target by a nanopore. FIG. 32 shows an exampletrace, ˜2350 secs after the addition of MgATP, comprising an initial,pre-dCas9 translocation event (B), stalling (C), and resumption oftranslocation (D). The resumption from the stall is highlighted andexpanded (E).

Sequences

Oligonucleotides

tracrRNA

The tracrRNA used throughout was a 67mer purchased from IDT (“Alt-R™”tracrRNA; catalogue #1072534)

Custom Oligonucleotides Used in this Filing:

INTERNAL REFERENCE SEQUENCE (5′-3′) AR130/5Phos/CAGACGCCGCAATATCAGCACCAACAGAAA/iBNA-meC//iBNA-A//iBNA-A//iBNA-meC//iBNA-meC/TTT ONLA11326333333333333333333333333333333TTTTTTTTTTTT/iSp18// iSp18//iSp18//iSp18/

GGC GTCTGCTTGGGTGTTTAACCT AR131/5Phos/TGTTCTGATCGGAACGATCG/iSp18//iSp18//iSp18//3 CholTEG/ AR132/5Phos/CGATCGTTCCGATCAGAACACAAAGATGTATTGCT AR133/5Phos/rCrUrUrCrGrCrGrGrCrArGrArUrArUrArArUrGrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAG AR134/5Phos/rCrCrGrArCrCrArCrGrCrCrArGrCrArUrArUrCrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAG AR135/5Phos/rUrGrCrArArCrGrGrUrCrGrArUrUrGrCrCrUrGrArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAG AR136/5Phos/rGrGrUrGrArArArUrArArUrCrCrCrGrUrUrCrArGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAG AR137/5Phos/rCrCrGrGrArCrGrUrUrArUrGrArUrUrUrArGrCrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAG AR138/5Phos/rCrUrUrCrGrCrGrGrCrArGrArUrArUrArArUrGrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR139/5Phos/rCrCrGrArCrCrArCrGrCrCrArGrCrArUrArUrCrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR140/5Phos/rUrGrCrArArCrGrGrUrCrGrArUrUrGrCrCrUrGrArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR141/5Phos/rGrGrUrGrArArArUrArArUrCrCrCrGrUrUrCrArGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR142/5Phos/rCrCrGrGrArCrGrUrUrArUrGrArUrUrUrArGrCrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR143/5Phos/rGrGrUrArCrGrCrCrArUrUrGrCrArArArCrGrCrArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR144/5Phos/rArCrGrArArUrGrArArCrUrArGrGrCrGrArUrArArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR145/5Phos/rArArArArArArGrCrCrGrGrArGrUrArGrArArGrArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR146/5Phos/rGrArCrGrUrCrArUrArArCrCrArUrGrArUrUrUrCrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG ONLA16941 TTGACCGCTCGCCTC/5Phos/ = 5′ phosphate moiety; /iBNA-meC/ = branched nucleic acid methylcytosine base; /iBNA-A/ = branched nucleic acid adenosine base;/3CholTEG/ = 3′ cholesterol moiety, linked via triethylene glycol; r= ribonucleotide base (RNA); 3 = C3 spacer; iSp18 = internal Sp18 spacerDNA Sample Libraries: Sequences and Preparation

-   -   3.6 kb derivative of enterobacteria phage lambda (“lambda 3.6        kb”)

>lambda_3.6kb GCCATCAGATTGTGTTTGTTAGTCGCTGCCATCAGATTGTGTTTGTTAGTCGCTTTTTTTTTTTGGAATTTTTTTTTTGGAATTTTTTTTTTGCGCTAACAACCTCCTGCCGTTTTGCCCGTGCATATCGGTCACGAACAAATCTGATTACTAAACACAGTAGCCTGGATTTGTTCTATCAGTAATCGACCTTATTCCTAATTAAATAGAGCAAATCCCCTTATTGGGGGTAAGACATGAAGATGCCAGAAAAACATGACCTGTTGGCCGCCATTCTCGCGGCAAAGGAACAAGGCATCGGGGCAATCCTTGCGTTTGCAATGGCGTACCTTCGCGGCAGATATAATGGCGGTGCGTTTACAAAAACAGTAATCGACGCAACGATGTGCGCCATTATCGCCTAGTTCATTCGTGACCTTCTCGACTTCGCCGGACTAAGTAGCAATCTCGCTTATATAACGAGCGTGTTTATCGGCTACATCGGTACTGACTCGATTGGTTCGCTTATCAAACGCTTCGCTGCTAAAAAAGCCGGAGTAGAAGATGGTAGAAATCAATAATCAACGTAAGGCGTTCCTCGATATGCTGGCGTGGTCGGAGGGAACTGATAACGGACGTCAGAAAACCAGAAATCATGGTTATGACGTCATTGTAGGCGGAGAGCTATTTACTGATTACTCCGATCACCCTCGCAAACTTGTCACGCTAAACCCAAAACTCAAATCAACAGGCGCCGGACGCTACCAGCTTCTTTCCCGTTGGTGGGATGCCTACCGCAAGCAGCTTGGCCTGAAAGACTTCTCTCCGAAAAGTCAGGACGCTGTGGCATTGCAGCAGATTAAGGAGCGTGGCGCTTTACCTATGATTGATCGTGGTGATATCCGTCAGGCAATCGACCGTTGCAGCAATATCTGGGCTTCACTGCCGGGCGCTGGTTATGGTCAGTTCGAGCATAAGGCTGACAGCCTGATTGCAAAATTCAAAGAAGCGGGCGGAACGGTCAGAGAGATTGATGTATGAGCAGAGTCACCGCGATTATCTCCGCTCTGGTTATCTGCATCATCGTCTGCCTGTCATGGGCTGTTAATCATTACCGTGATAACGCCATTACCTACAAAGCCCAGCGCGACAAAAATGCCAGAGAACTGAAGCTGGCGAACGCGGCAATTACTGACATGCAGATGCGTCAGCGTGATGTTGCTGCGCTCGATGCAAAATACACGAAGGAGTTAGCTGATGCTAAAGCTGAAAATGATGCTCTGCGTGATGATGTTGCCGCTGGTCGTCGTCGGTTGCACATCAAAGCAGTCTGTCAGTCAGTGCGTGAAGCCACCACCGCCTCCGGCGTGGATAATGCAGCCTCCCCCCGACTGGCAGACACCGCTGAACGGGATTATTTCACCCTCAGAGAGAGGCTGATCACTATGCAAAAACAACTGGAAGGAACCCAGAAGTATATTAATGAGCAGTGCAGATAGAGTTGCCCATATCGATGGGCAACTCATGCAATTATTGTGAGCAATACACACGCGCTTCCAGCGGAGTATAAATGCCTAAAGTAATAAAACCGAGCAATCCATTTACGAATGTTTGCTGGGTTTCTGTTTTAACAACATTTTCTGCGCCGCCACAAATTTTGGCTGCATCGACAGTTTTCTTCTGCCCAATTCCAGAAACGAAGAAATGATGGGTGATGGTTTCCTTTGGTGCTACTGCTGCCGGTTTGTTTTGAACAGTAAACGTCTGTTGAGCACATCCTGTAATAAGCAGGGCCAGCGCAGTAGCGAGTAGCATTTTTTTCATGGTGTTATTCCCGATGCTTTTTGAAGTTCGCAGAATCGTATGTGTAGAAAATTAAACAAACCCTAAACAATGAGTTGAAATTTCATATTGTTAATATTTATTAATGTATGTCAGGTGCGATGAATCGTCATTGTATTCCCGGATTAACTATGTCCACAGCCCTGACGGGGAACTTCTCTGCGGGAGTGTCCGGGAATAATTAAAACGATGCACACAGGGTTTAGCGCGTACACGTATTGCATTATGCCAACGCCCCGGTGCTGACACGGAAGAAACCGGACGTTATGATTTAGCGTGGAAAGATTTGTGTAGTGTTCTGAATGCTCTCAGTAAATAGTAATGAATTATCAAAGGTATAGTAATATCTTTTATGTTCATGGATATTTGTAACCCATCGGAAAACTCCTGCTTTAGCAAGATTTTCCCTGTATTGCTGAAATGTGATTTCTCTTGATTTCAACCTATCATAGGACGTTTCTATAAGATGCGTGTTTCTTGAGAATTTAACATTTACAACCTTTTTAAGTCCTTTTATTAACACGGTGTTATCGTTTTCTAACACGATGTGAATATTATCTGTGGCTAGATAGTAAATATAATGTGAGACGTTGTGACGTTTTAGTTCAGAATAAAACAATTCACAGTCTAAATCTTTTCGCACTTGATCGAATATTTCTTTAAAAATGGCAACCTGAGCCATTGGTAAAACCTTCCATGTGATACGAGGGCGCGTAGTTTGCATTATCGTTTTTATCGTTTCAATCTGGTCTGACCTCCTTGTGTTTTGTTGATGATTTATGTCAAATATTAGGAATGTTTTCACTTAATAGTATTGGTTGCGTAACAAAGTGCGGTCCTGCTGGCATTCTGGAGGGAAATACAACCGACAGATGTATGTAAGGCCAACGTGCTCAAATCTTCATACAGAAAGATTTGAAGTAATATTTTAACCGCTAGATGAAGAGCAAGCGCATGGAGCGACAAAATGAATAAAGAACAATCTGCTGATGATCCCTCCGTGGATCTGATTCGTGTAAAAAATATGCTTAATAGCACCATTTCTATGAGTTACCCTGATGTTGTAATTGCATGTATAGAACATAAGGTGTCTCTGGAAGCATTCAGAGCAATTGAGGCAGCGTTGGTGAAGCACGATAATAATATGAAGGATTATTCCCTGGTGGTTGACTGATCACCATAACTGCTAATCATTCAAACTATTTAGTCTGTGACAGAGCCAACACGCAGTCTGTCACTGTCAGGAAAGTGGTAAAACTGCAACTCAATTACTGCAATGCCCTCGTAATTAAGTGAATTTACAATATCGTCCTGTTCGGAGGGAAGAACGCGGGATGTTCATTCTTCATCACTTTTAATTGATGTATATGCTCTCTTTTCTGACGTTAGTCTCCGACGGCAGGCTTCAATGACCCAGGCTGAGAAATTCCCGGACCCTTTTTGCTCAAGAGCGATGTTAATTTGTTCAATCATTTGGTTAGGAAAGCGGATGTTGCGGGTTGTTGTTCTGCGGGTTCTGTTCTTCGTTGACATGAGGTTGCCCCGTATTCAGTGTCGCTGATTTGTATTGTCTGAAGTTGTTTTTACGTTAAGTTGATGCAGATCAATTAATACGATACCTGCGTCATAATTGATTATTTGACGTGGTTTGATGGCCTCCACGCACGTTGTGATATGTAGATGATAATCATTATCACTTTACGGGTCCTTTCCGGTGAAAAAAAAGGTACCAAAAAAAACATCGTCGTGAGTAGTGAACCGTAAGC

-   -   Enterobacteria phage lambda genome: GenBank accession ID        J02459.1    -   Seven-fragment derivative of bacteriophage lambda, ONLA15339

Bacteriophage lambda DNA (GenBank accession ID J02459.1; obtained fromNEB) was digested with SnaBI and BamHI-HF (NEB), and end-repaired anddA-tailed using an NEBNext Ultra End Repair/dA-Tailing Module (NEB).Helicase loaded adapters were ligated to dA-tailed DNA using NEBBlunt/TA Ligase Master Mix.

Fragment 1 (positions 1-5505 of phage lambda) GGGCGGCGAC CTCGCGGGTTTTCGCTATTT ATGAAAATTT TCCGGTTTAA GGCGTTTCCG TTCTTCTTCG TCATAACTTAATGTTTTTAT TTAAAATACC CTCTGAAAAG AAAGGAAACG ACAGGTGCTG AAAGCGAGGCTTTTTGGCCT CTGTCGTTTC CTTTCTCTGT TTTTGTCCGT GGAATGAACA ATGGAAGTCAACAAAAAGCA GCTGGCTGAC ATTTTCGGTG CGAGTATCCG TACCATTCAG AACTGGCAGGAACAGGGAAT GCCCGTTCTG CGAGGCGGTG GCAAGGGTAA TGAGGTGCTT TATGACTCTGCCGCCGTCAT AAAATGGTAT GCCGAAAGGG ATGCTGAAAT TGAGAACGAA AAGCTGCGCCGGGAGGTTGA AGAACTGCGG CAGGCCAGCG AGGCAGATCT CCAGCCAGGA ACTATTGAGTACGAACGCCA TCGACTTACG CGTGCGCAGG CCGACGCACA GGAACTGAAG AATGCCAGAGACTCCGCTGA AGTGGTGGAA ACCGCATTCT GTACTTTCGT GCTGTCGCGG ATCGCAGGTGAAATTGCCAG TATTCTCGAC GGGCTCCCCC TGTCGGTGCA GCGGCGTTTT CCGGAACTGGAAAACCGACA TGTTGATTTC CTGAAACGGG ATATCATCAA AGCCATGAAC AAAGCAGCCGCGCTGGATGA ACTGATACCG GGGTTGCTGA GTGAATATAT CGAACAGTCA GGTTAACAGGCTGCGGCATT TTGTCCGCGC CGGGCTTCGC TCACTGTTCA GGCCGGAGCC ACAGACCGCCGTTGAATGGG CGGATGCTAA TTACTATCTC CCGAAAGAAT CCGCATACCA GGAAGGGCGCTGGGAAACAC TGCCCTTTCA GCGGGCCATC ATGAATGCGA TGGGCAGCGA CTACATCCGTGAGGTGAATG TGGTGAAGTC TGCCCGTGTC GGTTATTCCA AAATGCTGCT GGGTGTTTATGCCTACTTTA TAGAGCATAA GCAGCGCAAC ACCCTTATCT GGTTGCCGAC GGATGGTGATGCCGAGAACT TTATGAAAAC CCACGTTGAG CCGACTATTC GTGATATTCC GTCGCTGCTGGCGCTGGCCC CGTGGTATGG CAAAAAGCAC CGGGATAACA CGCTCACCAT GAAGCGTTTCACTAATGGGC GTGGCTTCTG GTGCCTGGGC GGTAAAGCGG CAAAAAACTA CCGTGAAAAGTCGGTGGATG TGGCGGGTTA TGATGAACTT GCTGCTTTTG ATGATGATAT TGAACAGGAAGGCTCTCCGA CGTTCCTGGG TGACAAGCGT ATTGAAGGCT CGGTCTGGCC AAAGTCCATCCGTGGCTCCA CGCCAAAAGT GAGAGGCACC TGTCAGATTG AGCGTGCAGC CAGTGAATCCCCGCATTTTA TGCGTTTTCA TGTTGCCTGC CCGCATTGCG GGGAGGAGCA GTATCTTAAATTTGGCGACA AAGAGACGCC GTTTGGCCTC AAATGGACGC CGGATGACCC CTCCAGCGTGTTTTATCTCT GCGAGCATAA TGCCTGCGTC ATCCGCCAGC AGGAGCTGGA CTTTACTGATGCCCGTTATA TCTGCGAAAA GACCGGGATC TGGACCCGTG ATGGCATTCT CTGGTTTTCGTCATCCGGTG AAGAGATTGA GCCACCTGAC AGTGTGACCT TTCACATCTG GACAGCGTACAGCCCGTTCA CCACCTGGGT GCAGATTGTC AAAGACTGGA TGAAAACGAA AGGGGATACGGGAAAACGTA AAACCTTCGT AAACACCACG CTCGGTGAGA CGTGGGAGGC GAAAATTGGCGAACGTCCGG ATGCTGAAGT GATGGCAGAG CGGAAAGAGC ATTATTCAGC GCCCGTTCCTGACCGTGTGG CTTACCTGAC CGCCGGTATC GACTCCCAGC TGGACCGCTA CGAAATGCGCGTATGGGGAT GGGGGCCGGG TGAGGAAAGC TGGCTGATTG ACCGGCAGAT TATTATGGGCCGCCACGACG ATGAACAGAC GCTGCTGCGT GTGGATGAGG CCATCAATAA AACCTATACCCGCCGGAATG GTGCAGAAAT GTCGATATCC CGTATCTGCT GGGATACTGG CGGGATTGACCCGACCATTG TGTATGAACG CTCGAAAAAA CATGGGCTGT TCCGGGTGAT CCCCATTAAAGGGGCATCCG TCTACGGAAA GCCGGTGGCC AGCATGCCAC GTAAGCGAAA CAAAAACGGGGTTTACCTTA CCGAAATCGG TACGGATACC GCGAAAGAGC AGATTTATAA CCGCTTCACACTGACGCCGG AAGGGGATGA ACCGCTTCCC GGTGCCGTTC ACTTCCCGAA TAACCCGGATATTTTTGATC TGACCGAAGC GCAGCAGCTG ACTGCTGAAG AGCAGGTCGA AAAATGGGTGGATGGCAGGA AAAAAATACT GTGGGACAGC AAAAAGCGAC GCAATGAGGC ACTCGACTGCTTCGTTTATG CGCTGGCGGC GCTGCGCATC AGTATTTCCC GCTGGCAGCT GGATCTCAGTGCGCTGCTGG CGAGCCTGCA GGAAGAGGAT GGTGCAGCAA CCAACAAGAA AACACTGGCAGATTACGCCC GTGCCTTATC CGGAGAGGAT GAATGACGCG ACAGGAAGAA CTTGCCGCTGCCCGTGCGGC ACTGCATGAC CTGATGACAG GTAAACGGGT GGCAACAGTA CAGAAAGACGGACGAAGGGT GGAGTTTACG GCCACTTCCG TGTCTGACCT GAAAAAATAT ATTGCAGAGCTGGAAGTGCA GACCGGCATG ACACAGCGAC GCAGGGGACC TGCAGGATTT TATGTATGAAAACGCCCACC ATTCCCACCC TTCTGGGGCC GGACGGCATG ACATCGCTGC GCGAATATGCCGGTTATCAC GGCGGTGGCA GCGGATTTGG AGGGCAGTTG CGGTCGTGGA ACCCACCGAGTGAAAGTGTG GATGCAGCCC TGTTGCCCAA CTTTACCCGT GGCAATGCCC GCGCAGACGATCTGGTACGC AATAACGGCT ATGCCGCCAA CGCCATCCAG CTGCATCAGG ATCATATCGTCGGGTCTTTT TTCCGGCTCA GTCATCGCCC AAGCTGGCGC TATCTGGGCA TCGGGGAGGAAGAAGCCCGT GCCTTTTCCC GCGAGGTTGA AGCGGCATGG AAAGAGTTTG CCGAGGATGACTGCTGCTGC ATTGACGTTG AGCGAAAACG CACGTTTACC ATGATGATTC GGGAAGGTGTGGCCATGCAC GCCTTTAACG GTGAACTGTT CGTTCAGGCC ACCTGGGATA CCAGTTCGTCGCGGCTTTTC CGGACACAGT TCCGGATGGT CAGCCCGAAG CGCATCAGCA ACCCGAACAATACCGGCGAC AGCCGGAACT GCCGTGCCGG TGTGCAGATT AATGACAGCG GTGCGGCGCTGGGATATTAC GTCAGCGAGG ACGGGTATCC TGGCTGGATG CCGCAGAAAT GGACATGGATACCCCGTGAG TTACCCGGCG GGCGCGCCTC GTTCATTCAC GTTTTTGAAC CCGTGGAGGACGGGCAGACT CGCGGTGCAA ATGTGTTTTA CAGCGTGATG GAGCAGATGA AGATGCTCGACACGCTGCAG AACACGCAGC TGCAGAGCGC CATTGTGAAG GCGATGTATG CCGCCACCATTGAGAGTGAG CTGGATACGC AGTCAGCGAT GGATTTTATT CTGGGCGCGA ACAGTCAGGAGCAGCGGGAA AGGCTGACCG GCTGGATTGG TGAAATTGCC GCGTATTACG CCGCAGCGCCGGTCCGGCTG GGAGGCGCAA AAGTACCGCA CCTGATGCCG GGTGACTCAC TGAACCTGCAGACGGCTCAG GATACGGATA ACGGCTACTC CGTGTTTGAG CAGTCACTGC TGCGGTATATCGCTGCCGGG CTGGGTGTCT CGTATGAGCA GCTTTCCCGG AATTACGCCC AGATGAGCTACTCCACGGCA CGGGCCAGTG CGAACGAGTC GTGGGCGTAC TTTATGGGGC GGCGAAAATTCGTCGCATCC CGTCAGGCGA GCCAGATGTT TCTGTGCTGG CTGGAAGAGG CCATCGTTCGCCGCGTGGTG ACGTTACCTT CAAAAGCGCG CTTCAGTTTT CAGGAAGCCC GCAGTGCCTGGGGGAACTGC GACTGGATAG GCTCCGGTCG TATGGCCATC GATGGTCTGA AAGAAGTTCAGGAAGCGGTG ATGCTGATAG AAGCCGGACT GAGTACCTAC GAGAAAGAGT GCGCAAAACGCGGTGACGAC TATCAGGAAA TTTTTGCCCA GCAGGTCCGT GAAACGATGG AGCGCCGTGCAGCCGGTCTT AAACCGCCCG CCTGGGCGGC TGCAGCATTT GAATCCGGGC TGCGACAATCAACAGAGGAG GAGAAGAGTG ACAGCAGAGC TGCGTAATCT CCCGCATATT GCCAGCATGGCCTTTAATGA GCCGCTGATG CTTGAACCCG CCTATGCGCG GGTTTTCTTT TGTGCGCTTGCAGGCCAGCT TGGGATCAGC AGCCTGACGG ATGCGGTGTC CGGCGACAGC CTGACTGCCCAGGAGGCACT CGCGACGCTG GCATTATCCG GTGATGATGA CGGACCACGA CAGGCCCGCAGTTATCAGGT CATGAACGGC ATCGCCGTGC TGCCGGTGTC CGGCACGCTG GTCAGCCGGACGCGGGCGCT GCAGCCGTAC TCGGGGATGA CCGGTTACAA CGGCATTATC GCCCGTCTGCAACAGGCTGC CAGCGATCCG ATGGTGGACG GCATTCTGCT CGATATGGAC ACGCCCGGCGGGATGGTGGC GGGGGCATTT GACTGCGCTG ACATCATCGC CCGTGTGCGT GACATAAAACCGGTATGGGC GCTTGCCAAC GACATGAACT GCAGTGCAGG TCAGTTGCTT GCCAGTGCCGCCTCCCGGCG TCTGGTCACG CAGACCGCCC GGACAGGCTC CATCGGCGTC ATGATGGCTCACAGTAATTA CGGTGCTGCG CTGGAGAAAC AGGGTGTGGA AATCACGCTG ATTTACAGCGGCAGCCATAA GGTGGATGGC AACCCCTACA GCCATCTTCC GGATGACGTC CGGGAGACACTGCAGTCCCG GATGGACGCA ACCCGCCAGA TGTTTGCGCA GAAGGTGTCG GCATATACCGGCCTGTCCGT GCAGGTTGTG CTGGATACCG AGGCTGCAGT GTACAGCGGT CAGGAGGCCATTGATGCCGG ACTGGCTGAT GAACTTGTTA ACAGCACCGA TGCGATCACC GTCATGCGTGATGCACTGGA TGCACGTAAA TCCCGTCTCT CAGGAGGGCG AATGACCAAA GAGACTCAATCAACAACTGT TTCAGCCACT GCTTCGCAGG CTGACGTTAC TGACGTGGTG CCAGCGACGGAGGGCGAGAA CGCCAGCGCG GCGCAGCCGG ACGTGAACGC GCAGATCACC GCAGCGGTTGCGGCAGAAAA CAGCCGCATT ATGGG Fragment 2 (positions 5509-12910 of phagelambda) GATCCTCAAC TGTGAGGAGG CTCACGGACG CGAAGAACAG GCACGCGTGCTGGCAGAAAC CCCCGGTATG ACCGTGAAAA CGGCCCGCCG CATTCTGGCC GCAGCACCACAGAGTGCACA GGCGCGCAGT GACACTGCGC TGGATCGTCT GATGCAGGGG GCACCGGCACCGCTGGCTGC AGGTAACCCG GCATCTGATG CCGTTAACGA TTTGCTGAAC ACACCAGTGTAAGGGATGTT TATGACGAGC AAAGAAACCT TTACCCATTA CCAGCCGCAG GGCAACAGTGACCCGGCTCA TACCGCAACC GCGCCCGGCG GATTGAGTGC GAAAGCGCCT GCAATGACCCCGCTGATGCT GGACACCTCC AGCCGTAAGC TGGTTGCGTG GGATGGCACC ACCGACGGTGCTGCCGTTGG CATTCTTGCG GTTGCTGCTG ACCAGACCAG CACCACGCTG ACGTTCTACAAGTCCGGCAC GTTCCGTTAT GAGGATGTGC TCTGGCCGGA GGCTGCCAGC GACGAGACGAAAAAACGGAC CGCGTTTGCC GGAACGGCAA TCAGCATCGT TTAACTTTAC CCTTCATCACTAAAGGCCGC CTGTGCGGCT TTTTTTACGG GATTTTTTTA TGTCGATGTA CACAACCGCCCAACTGCTGG CGGCAAATGA GCAGAAATTT AAGTTTGATC CGCTGTTTCT GCGTCTCTTTTTCCGTGAGA GCTATCCCTT CACCACGGAG AAAGTCTATC TCTCACAAAT TCCGGGACTGGTAAACATGG CGCTGTACGT TTCGCCGATT GTTTCCGGTG AGGTTATCCG TTCCCGTGGCGGCTCCACCT CTGAATTTAC GCCGGGATAT GTCAAGCCGA AGCATGAAGT GAATCCGCAGATGACCCTGC GTCGCCTGCC GGATGAAGAT CCGCAGAATC TGGCGGACCC GGCTTACCGCCGCCGTCGCA TCATCATGCA GAACATGCGT GACGAAGAGC TGGCCATTGC TCAGGTCGAAGAGATGCAGG CAGTTTCTGC CGTGCTTAAG GGCAAATACA CCATGACCGG TGAAGCCTTCGATCCGGTTG AGGTGGATAT GGGCCGCAGT GAGGAGAATA ACATCACGCA GTCCGGCGGCACGGAGTGGA GCAAGCGTGA CAAGTCCACG TATGACCCGA CCGACGATAT CGAAGCCTACGCGCTGAACG CCAGCGGTGT GGTGAATATC ATCGTGTTCG ATCCGAAAGG CTGGGCGCTGTTCCGTTCCT TCAAAGCCGT CAAGGAGAAG CTGGATACCC GTCGTGGCTC TAATTCCGAGCTGGAGACAG CGGTGAAAGA CCTGGGCAAA GCGGTGTCCT ATAAGGGGAT GTATGGCGATGTGGCCATCG TCGTGTATTC CGGACAGTAC GTGGAAAACG GCGTCAAAAA GAACTTCCTGCCGGACAACA CGATGGTGCT GGGGAACACT CAGGCACGCG GTCTGCGCAC CTATGGCTGCATTCAGGATG CGGACGCACA GCGCGAAGGC ATTAACGCCT CTGCCCGTTA CCCGAAAAACTGGGTGACCA CCGGCGATCC GGCGCGTGAG TTCACCATGA TTCAGTCAGC ACCGCTGATGCTGCTGGCTG ACCCTGATGA GTTCGTGTCC GTACAACTGG CGTAATCATG GCCCTTCGGGGCCATTGTTT CTCTGTGGAG GAGTCCATGA CGAAAGATGA ACTGATTGCC CGTCTCCGCTCGCTGGGTGA ACAACTGAAC CGTGATGTCA GCCTGACGGG GACGAAAGAA GAACTGGCGCTCCGTGTGGC AGAGCTGAAA GAGGAGCTTG ATGACACGGA TGAAACTGCC GGTCAGGACACCCCTCTCAG CCGGGAAAAT GTGCTGACCG GACATGAAAA TGAGGTGGGA TCAGCGCAGCCGGATACCGT GATTCTGGAT ACGTCTGAAC TGGTCACGGT CGTGGCACTG GTGAAGCTGCATACTGATGC ACTTCACGCC ACGCGGGATG AACCTGTGGC ATTTGTGCTG CCGGGAACGGCGTTTCGTGT CTCTGCCGGT GTGGCAGCCG AAATGACAGA GCGCGGCCTG GCCAGAATGCAATAACGGGA GGCGCTGTGG CTGATTTCGA TAACCTGTTC GATGCTGCCA TTGCCCGCGCCGATGAAACG ATACGCGGGT ACATGGGAAC GTCAGCCACC ATTACATCCG GTGAGCAGTCAGGTGCGGTG ATACGTGGTG TTTTTGATGA CCCTGAAAAT ATCAGCTATG CCGGACAGGGCGTGCGCGTT GAAGGCTCCA GCCCGTCCCT GTTTGTCCGG ACTGATGAGG TGCGGCAGCTGCGGCGTGGA GACACGCTGA CCATCGGTGA GGAAAATTTC TGGGTAGATC GGGTTTCGCCGGATGATGGC GGAAGTTGTC ATCTCTGGCT TGGACGGGGC GTACCGCCTG CCGTTAACCGTCGCCGCTGA AAGGGGGATG TATGGCCATA AAAGGTCTTG AGCAGGCCGT TGAAAACCTCAGCCGTATCA GCAAAACGGC GGTGCCTGGT GCCGCCGCAA TGGCCATTAA CCGCGTTGCTTCATCCGCGA TATCGCAGTC GGCGTCACAG GTTGCCCGTG AGACAAAGGT ACGCCGGAAACTGGTAAAGG AAAGGGCCAG GCTGAAAAGG GCCACGGTCA AAAATCCGCA GGCCAGAATCAAAGTTAACC GGGGGGATTT GCCCGTAATC AAGCTGGGTA ATGCGCGGGT TGTCCTTTCGCGCCGCAGGC GTCGTAAAAA GGGGCAGCGT TCATCCCTGA AAGGTGGCGG CAGCGTGCTTGTGGTGGGTA ACCGTCGTAT TCCCGGCGCG TTTATTCAGC AACTGAAAAA TGGCCGGTGGCATGTCATGC AGCGTGTGGC TGGGAAAAAC CGTTACCCCA TTGATGTGGT GAAAATCCCGATGGCGGTGC CGCTGACCAC GGCGTTTAAA CAAAATATTG AGCGGATACG GCGTGAACGTCTTCCGAAAG AGCTGGGCTA TGCGCTGCAG CATCAACTGA GGATGGTAAT AAAGCGATGAAACATACTGA ACTCCGTGCA GCCGTACTGG ATGCACTGGA GAAGCATGAC ACCGGGGCGACGTTTTTTGA TGGTCGCCCC GCTGTTTTTG ATGAGGCGGA TTTTCCGGCA GTTGCCGTTTATCTCACCGG CGCTGAATAC ACGGGCGAAG AGCTGGACAG CGATACCTGG CAGGCGGAGCTGCATATCGA AGTTTTCCTG CCTGCTCAGG TGCCGGATTC AGAGCTGGAT GCGTGGATGGAGTCCCGGAT TTATCCGGTG ATGAGCGATA TCCCGGCACT GTCAGATTTG ATCACCAGTATGGTGGCCAG CGGCTATGAC TACCGGCGCG ACGATGATGC GGGCTTGTGG AGTTCAGCCGATCTGACTTA TGTCATTACC TATGAAATGT GAGGACGCTA TGCCTGTACC AAATCCTACAATGCCGGTGA AAGGTGCCGG GACCACCCTG TGGGTTTATA AGGGGAGCGG TGACCCTTACGCGAATCCGC TTTCAGACGT TGACTGGTCG CGTCTGGCAA AAGTTAAAGA CCTGACGCCCGGCGAACTGA CCGCTGAGTC CTATGACGAC AGCTATCTCG ATGATGAAGA TGCAGACTGGACTGCGACCG GGCAGGGGCA GAAATCTGCC GGAGATACCA GCTTCACGCT GGCGTGGATGCCCGGAGAGC AGGGGCAGCA GGCGCTGCTG GCGTGGTTTA ATGAAGGCGA TACCCGTGCCTATAAAATCC GCTTCCCGAA CGGCACGGTC GATGTGTTCC GTGGCTGGGT CAGCAGTATCGGTAAGGCGG TGACGGCGAA GGAAGTGATC ACCCGCACGG TGAAAGTCAC CAATGTGGGACGTCCGTCGA TGGCAGAAGA TCGCAGCACG GTAACAGCGG CAACCGGCAT GACCGTGACGCCTGCCAGCA CCTCGGTGGT GAAAGGGCAG AGCACCACGC TGACCGTGGC CTTCCAGCCGGAGGGCGTAA CCGACAAGAG CTTTCGTGCG GTGTCTGCGG ATAAAACAAA AGCCACCGTGTCGGTCAGTG GTATGACCAT CACCGTGAAC GGCGTTGCTG CAGGCAAGGT CAACATTCCGGTTGTATCCG GTAATGGTGA GTTTGCTGCG GTTGCAGAAA TTACCGTCAC CGCCAGTTAATCCGGAGAGT CAGCGATGTT CCTGAAAACC GAATCATTTG AACATAACGG TGTGACCGTCACGCTTTCTG AACTGTCAGC CCTGCAGCGC ATTGAGCATC TCGCCCTGAT GAAACGGCAGGCAGAACAGG CGGAGTCAGA CAGCAACCGG AAGTTTACTG TGGAAGACGC CATCAGAACCGGCGCGTTTC TGGTGGCGAT GTCCCTGTGG CATAACCATC CGCAGAAGAC GCAGATGCCGTCCATGAATG AAGCCGTTAA ACAGATTGAG CAGGAAGTGC TTACCACCTG GCCCACGGAGGCAATTTCTC ATGCTGAAAA CGTGGTGTAC CGGCTGTCTG GTATGTATGA GTTTGTGGTGAATAATGCCC CTGAACAGAC AGAGGACGCC GGGCCCGCAG AGCCTGTTTC TGCGGGAAAGTGTTCGACGG TGAGCTGAGT TTTGCCCTGA AACTGGCGCG TGAGATGGGG CGACCCGACTGGCGTGCCAT GCTTGCCGGG ATGTCATCCA CGGAGTATGC CGACTGGCAC CGCTTTTACAGTACCCATTA TTTTCATGAT GTTCTGCTGG ATATGCACTT TTCCGGGCTG ACGTACACCGTGCTCAGCCT GTTTTTCAGC GATCCGGATA TGCATCCGCT GGATTTCAGT CTGCTGAACCGGCGCGAGGC TGACGAAGAG CCTGAAGATG ATGTGCTGAT GCAGAAAGCG GCAGGGCTTGCCGGAGGTGT CCGCTTTGGC CCGGACGGGA ATGAAGTTAT CCCCGCTTCC CCGGATGTGGCGGACATGAC GGAGGATGAC GTAATGCTGA TGACAGTATC AGAAGGGATC GCAGGAGGAGTCCGGTATGG CTGAACCGGT AGGCGATCTG GTCGTTGATT TGAGTCTGGA TGCGGCCAGATTTGACGAGC AGATGGCCAG AGTCAGGCGT CATTTTTCTG GTACGGAAAG TGATGCGAAAAAAACAGCGG CAGTCGTTGA ACAGTCGCTG AGCCGACAGG CGCTGGCTGC ACAGAAAGCGGGGATTTCCG TCGGGCAGTA TAAAGCCGCC ATGCGTATGC TGCCTGCACA GTTCACCGACGTGGCCACGC AGCTTGCAGG CGGGCAAAGT CCGTGGCTGA TCCTGCTGCA ACAGGGGGGGCAGGTGAAGG ACTCCTTCGG CGGGATGATC CCCATGTTCA GGGGGCTTGC CGGTGCGATCACCCTGCCGA TGGTGGGGGC CACCTCGCTG GCGGTGGCGA CCGGTGCGCT GGCGTATGCCTGGTATCAGG GCAACTCAAC CCTGTCCGAT TTCAACAAAA CGCTGGTCCT TTCCGGCAATCAGGCGGGAC TGACGGCAGA TCGTATGCTG GTCCTGTCCA GAGCCGGGCA GGCGGCAGGGCTGACGTTTA ACCAGACCAG CGAGTCACTC AGCGCACTGG TTAAGGCGGG GGTAAGCGGTGAGGCTCAGA TTGCGTCCAT CAGCCAGAGT GTGGCGCGTT TCTCCTCTGC ATCCGGCGTGGAGGTGGACA AGGTCGCTGA AGCCTTCGGG AAGCTGACCA CAGACCCGAC GTCGGGGCTGACGGCGATGG CTCGCCAGTT CCATAACGTG TCGGCGGAGC AGATTGCGTA TGTTGCTCAGTTGCAGCGTT CCGGCGATGA AGCCGGGGCA TTGCAGGCGG CGAACGAGGC CGCAACGAAAGGGTTTGATG ACCAGACCCG CCGCCTGAAA GAGAACATGG GCACGCTGGA GACCTGGGCAGACAGGACTG CGCGGGCATT CAAATCCATG TGGGATGCGG TGCTGGATAT TGGTCGTCCTGATACCGCGC AGGAGATGCT GATTAAGGCA GAGGCTGCGT ATAAGAAAGC AGACGACATCTGGAATCTGC GCAAGGATGA TTATTTTGTT AACGATGAAG CGCGGGCGCG TTACTGGGATGATCGTGAAA AGGCCCGTCT TGCGCTTGAA GCCGCCCGAA AGAAGGCTGA GCAGCAGACTCAACAGGACA AAAATGCGCA GCAGCAGAGC GATACCGAAG CGTCACGGCT GAAATATACCGAAGAGGCGC AGAAGGCTTA CGAACGGCTG CAGACGCCGC TGGAGAAATA TACCGCCCGTCAGGAAGAAC TGAACAAGGC ACTGAAAGAC GGGAAAATCC TGCAGGCGGA TTACAACACGCTGATGGCGG CGGCGAAAAA GGATTATGAA GCGACGCTGA AAAAGCCGAA ACAGTCCAGCGTGAAGGTGT CTGCGGGCGA TCGTCAGGAA GACAGTGCTC ATGCTGCCCT GCTGACGCTTCAGGCAGAAC TCCGGACGCT GGAGAAGCAT GCCGGAGCAA ATGAGAAAAT CAGCCAGCAGCGCCGGGATT TGTGGAAGGC GGAGAGTCAG TTCGCGGTAC TGGAGGAGGC GGCGCAACGTCGCCAGCTGT CTGCACAGGA GAAATCCCTG CTGGCGCATA AAGATGAGAC GCTGGAGTACAAACGCCAGC TGGCTGCACT TGGCGACAAG GTTAC Fragment 3 (positions 12910-22346of phage lambda) GTATCAGGAG CGCCTGAACG CGCTGGCGCA GCAGGCGGAT AAATTCGCACAGCAGCAACG GGCAAAACGG GCCGCCATTG ATGCGAAAAG CCGGGGGCTG ACTGACCGGCAGGCAGAACG GGAAGCCACG GAACAGCGCC TGAAGGAACA GTATGGCGAT AATCCGCTGGCGCTGAATAA CGTCATGTCA GAGCAGAAAA AGACCTGGGC GGCTGAAGAC CAGCTTCGCGGGAACTGGAT GGCAGGCCTG AAGTCCGGCT GGAGTGAGTG GGAAGAGAGC GCCACGGACAGTATGTCGCA GGTAAAAAGT GCAGCCACGC AGACCTTTGA TGGTATTGCA CAGAATATGGCGGCGATGCT GACCGGCAGT GAGCAGAACT GGCGCAGCTT CACCCGTTCC GTGCTGTCCATGATGACAGA AATTCTGCTT AAGCAGGCAA TGGTGGGGAT TGTCGGGAGT ATCGGCAGCGCCATTGGCGG GGCTGTTGGT GGCGGCGCAT CCGCGTCAGG CGGTACAGCC ATTCAGGCCGCTGCGGCGAA ATTCCATTTT GCAACCGGAG GATTTACGGG AACCGGCGGC AAATATGAGCCAGCGGGGAT TGTTCACCGT GGTGAGTTTG TCTTCACGAA GGAGGCAACC AGCCGGATTGGCGTGGGGAA TCTTTACCGG CTGATGCGCG GCTATGCCAC CGGCGGTTAT GTCGGTACACCGGGCAGCAT GGCAGACAGC CGGTCGCAGG CGTCCGGGAC GTTTGAGCAG AATAACCATGTGGTGATTAA CAACGACGGC ACGAACGGGC AGATAGGTCC GGCTGCTCTG AAGGCGGTGTATGACATGGC CCGCAAGGGT GCCCGTGATG AAATTCAGAC ACAGATGCGT GATGGTGGCCTGTTCTCCGG AGGTGGACGA TGAAGACCTT CCGCTGGAAA GTGAAACCCG GTATGGATGTGGCTTCGGTC CCTTCTGTAA GAAAGGTGCG CTTTGGTGAT GGCTATTCTC AGCGAGCGCCTGCCGGGCTG AATGCCAACC TGAAAACGTA CAGCGTGACG CTTTCTGTCC CCCGTGAGGAGGCCACGGTA CTGGAGTCGT TTCTGGAAGA GCACGGGGGC TGGAAATCCT TTCTGTGGACGCCGCCTTAT GAGTGGCGGC AGATAAAGGT GACCTGCGCA AAATGGTCGT CGCGGGTCAGTATGCTGCGT GTTGAGTTCA GCGCAGAGTT TGAACAGGTG GTGAACTGAT GCAGGATATCCGGCAGGAAA CACTGAATGA ATGCACCCGT GCGGAGCAGT CGGCCAGCGT GGTGCTCTGGGAAATCGACC TGACAGAGGT CGGTGGAGAA CGTTATTTTT TCTGTAATGA GCAGAACGAAAAAGGTGAGC CGGTCACCTG GCAGGGGCGA CAGTATCAGC CGTATCCCAT TCAGGGGAGCGGTTTTGAAC TGAATGGCAA AGGCACCAGT ACGCGCCCCA CGCTGACGGT TTCTAACCTGTACGGTATGG TCACCGGGAT GGCGGAAGAT ATGCAGAGTC TGGTCGGCGG AACGGTGGTCCGGCGTAAGG TTTACGCCCG TTTTCTGGAT GCGGTGAACT TCGTCAACGG AAACAGTTACGCCGATCCGG AGCAGGAGGT GATCAGCCGC TGGCGCATTG AGCAGTGCAG CGAACTGAGCGCGGTGAGTG CCTCCTTTGT ACTGTCCACG CCGACGGAAA CGGATGGCGC TGTTTTTCCGGGACGTATCA TGCTGGCCAA CACCTGCACC TGGACCTATC GCGGTGACGA GTGCGGTTATAGCGGTCCGG CTGTCGCGGA TGAATATGAC CAGCCAACGT CCGATATCAC GAAGGATAAATGCAGCAAAT GCCTGAGCGG TTGTAAGTTC CGCAATAACG TCGGCAACTT TGGCGGCTTCCTTTCCATTA ACAAACTTTC GCAGTAAATC CCATGACACA GACAGAATCA GCGATTCTGGCGCACGCCCG GCGATGTGCG CCAGCGGAGT CGTGCGGCTT CGTGGTAAGC ACGCCGGAGGGGGAAAGATA TTTCCCCTGC GTGAATATCT CCGGTGAGCC GGAGGCTATT TCCGTATGTCGCCGGAAGAC TGGCTGCAGG CAGAAATGCA GGGTGAGATT GTGGCGCTGG TCCACAGCCACCCCGGTGGT CTGCCCTGGC TGAGTGAGGC CGACCGGCGG CTGCAGGTGC AGAGTGATTTGCCGTGGTGG CTGGTCTGCC GGGGGACGAT TCATAAGTTC CGCTGTGTGC CGCATCTCACCGGGCGGCGC TTTGAGCACG GTGTGACGGA CTGTTACACA CTGTTCCGGG ATGCTTATCATCTGGCGGGG ATTGAGATGC CGGACTTTCA TCGTGAGGAT GACTGGTGGC GTAACGGCCAGAATCTCTAT CTGGATAATC TGGAGGCGAC GGGGCTGTAT CAGGTGCCGT TGTCAGCGGCACAGCCGGGC GATGTGCTGC TGTGCTGTTT TGGTTCATCA GTGCCGAATC ACGCCGCAATTTACTGCGGC GACGGCGAGC TGCTGCACCA TATTCCTGAA CAACTGAGCA AACGAGAGAGGTACACCGAC AAATGGCAGC GACGCACACA CTCCCTCTGG CGTCACCGGG CATGGCGCGCATCTGCCTTT ACGGGGATTT ACAACGATTT GGTCGCCGCA TCGACCTTCG TGTGAAAACGGGGGCTGAAG CCATCCGGGC ACTGGCCACA CAGCTCCCGG CGTTTCGTCA GAAACTGAGCGACGGCTGGT ATCAGGTACG GATTGCCGGG CGGGACGTCA GCACGTCCGG GTTAACGGCGCAGTTACATG AGACTCTGCC TGATGGCGCT GTAATTCATA TTGTTCCCAG AGTCGCCGGGGCCAAGTCAG GTGGCGTATT CCAGATTGTC CTGGGGGCTG CCGCCATTGC CGGATCATTCTTTACCGCCG GAGCCACCCT TGCAGCATGG GGGGCAGCCA TTGGGGCCGG TGGTATGACCGGCATCCTGT TTTCTCTCGG TGCCAGTATG GTGCTCGGTG GTGTGGCGCA GATGCTGGCACCGAAAGCCA GAACTCCCCG TATACAGACA ACGGATAACG GTAAGCAGAA CACCTATTTCTCCTCACTGG ATAACATGGT TGCCCAGGGC AATGTTCTGC CTGTTCTGTA CGGGGAAATGCGCGTGGGGT CACGCGTGGT TTCTCAGGAG ATCAGCACGG CAGACGAAGG GGACGGTGGTCAGGTTGTGG TGATTGGTCG CTGATGCAAA ATGTTTTATG TGAAACCGCC TGCGGGCGGTTTTGTCATTT ATGGAGCGTG AGGAATGGGT AAAGGAAGCA GTAAGGGGCA TACCCCGCGCGAAGCGAAGG ACAACCTGAA GTCCACGCAG TTGCTGAGTG TGATCGATGC CATCAGCGAAGGGCCGATTG AAGGTCCGGT GGATGGCTTA AAAAGCGTGC TGCTGAACAG TACGCCGGTGCTGGACACTG AGGGGAATAC CAACATATCC GGTGTCACGG TGGTGTTCCG GGCTGGTGAGCAGGAGCAGA CTCCGCCGGA GGGATTTGAA TCCTCCGGCT CCGAGACGGT GCTGGGTACGGAAGTGAAAT ATGACACGCC GATCACCCGC ACCATTACGT CTGCAAACAT CGACCGTCTGCGCTTTACCT TCGGTGTACA GGCACTGGTG GAAACCACCT CAAAGGGTGA CAGGAATCCGTCGGAAGTCC GCCTGCTGGT TCAGATACAA CGTAACGGTG GCTGGGTGAC GGAAAAAGACATCACCATTA AGGGCAAAAC CACCTCGCAG TATCTGGCCT CGGTGGTGAT GGGTAACCTGCCGCCGCGCC CGTTTAATAT CCGGATGCGC AGGATGACGC CGGACAGCAC CACAGACCAGCTGCAGAACA AAACGCTCTG GTCGTCATAC ACTGAAATCA TCGATGTGAA ACAGTGCTACCCGAACACGG CACTGGTCGG CGTGCAGGTG GACTCGGAGC AGTTCGGCAG CCAGCAGGTGAGCCGTAATT ATCATCTGCG CGGGCGTATT CTGCAGGTGC CGTCGAACTA TAACCCGCAGACGCGGCAAT ACAGCGGTAT CTGGGACGGA ACGTTTAAAC CGGCATACAG CAACAACATGGCCTGGTGTC TGTGGGATAT GCTGACCCAT CCGCGCTACG GCATGGGGAA ACGTCTTGGTGCGGCGGATG TGGATAAATG GGCGCTGTAT GTCATCGGCC AGTACTGCGA CCAGTCAGTGCCGGACGGCT TTGGCGGCAC GGAGCCGCGC ATCACCTGTA ATGCGTACCT GACCACACAGCGTAAGGCGT GGGATGTGCT CAGCGATTTC TGCTCGGCGA TGCGCTGTAT GCCGGTATGGAACGGGCAGA CGCTGACGTT CGTGCAGGAC CGACCGTCGG ATAAGACGTG GACCTATAACCGCAGTAATG TGGTGATGCC GGATGATGGC GCGCCGTTCC GCTACAGCTT CAGCGCCCTGAAGGACCGCC ATAATGCCGT TGAGGTGAAC TGGATTGACC CGAACAACGG CTGGGAGACGGCGACAGAGC TTGTTGAAGA TACGCAGGCC ATTGCCCGTT ACGGTCGTAA TGTTACGAAGATGGATGCCT TTGGCTGTAC CAGCCGGGGG CAGGCACACC GCGCCGGGCT GTGGCTGATTAAAACAGAAC TGCTGGAAAC GCAGACCGTG GATTTCAGCG TCGGCGCAGA AGGGCTTCGCCATGTACCGG GCGATGTTAT TGAAATCTGC GATGATGACT ATGCCGGTAT CAGCACCGGTGGTCGTGTGC TGGCGGTGAA CAGCCAGACC CGGACGCTGA CGCTCGACCG TGAAATCACGCTGCCATCCT CCGGTACCGC GCTGATAAGC CTGGTTGACG GAAGTGGCAA TCCGGTCAGCGTGGAGGTTC AGTCCGTCAC CGACGGCGTG AAGGTAAAAG TGAGCCGTGT TCCTGACGGTGTTGCTGAAT ACAGCGTATG GGAGCTGAAG CTGCCGACGC TGCGCCAGCG ACTGTTCCGCTGCGTGAGTA TCCGTGAGAA CGACGACGGC ACGTATGCCA TCACCGCCGT GCAGCATGTGCCGGAAAAAG AGGCCATCGT GGATAACGGG GCGCACTTTG ACGGCGAACA GAGTGGCACGGTGAATGGTG TCACGCCGCC AGCGGTGCAG CACCTGACCG CAGAAGTCAC TGCAGACAGCGGGGAATATC AGGTGCTGGC GCGATGGGAC ACACCGAAGG TGGTGAAGGG CGTGAGTTTCCTGCTCCGTC TGACCGTAAC AGCGGACGAC GGCAGTGAGC GGCTGGTCAG CACGGCCCGGACGACGGAAA CCACATACCG CTTCACGCAA CTGGCGCTGG GGAACTACAG GCTGACAGTCCGGGCGGTAA ATGCGTGGGG GCAGCAGGGC GATCCGGCGT CGGTATCGTT CCGGATTGCCGCACCGGCAG CACCGTCGAG GATTGAGCTG ACGCCGGGCT ATTTTCAGAT AACCGCCACGCCGCATCTTG CCGTTTATGA CCCGACGGTA CAGTTTGAGT TCTGGTTCTC GGAAAAGCAGATTGCGGATA TCAGACAGGT TGAAACCAGC ACGCGTTATC TTGGTACGGC GCTGTACTGGATAGCCGCCA GTATCAATAT CAAACCGGGC CATGATTATT ACTTTTATAT CCGCAGTGTGAACACCGTTG GCAAATCGGC ATTCGTGGAG GCCGTCGGTC GGGCGAGCGA TGATGCGGAAGGTTACCTGG ATTTTTTCAA AGGCAAGATA ACCGAATCCC ATCTCGGCAA GGAGCTGCTGGAAAAAGTCG AGCTGACGGA GGATAACGCC AGCAGACTGG AGGAGTTTTC GAAAGAGTGGAAGGATGCCA GTGATAAGTG GAATGCCATG TGGGCTGTCA AAATTGAGCA GACCAAAGACGGCAAACATT ATGTCGCGGG TATTGGCCTC AGCATGGAGG ACACGGAGGA AGGCAAACTGAGCCAGTTTC TGGTTGCCGC CAATCGTATC GCATTTATTG ACCCGGCAAA CGGGAATGAAACGCCGATGT TTGTGGCGCA GGGCAACCAG ATATTCATGA ACGACGTGTT CCTGAAGCGCCTGACGGCCC CCACCATTAC CAGCGGCGGC AATCCTCCGG CCTTTTCCCT GACACCGGACGGAAAGCTGA CCGCTAAAAA TGCGGATATC AGTGGCAGTG TGAATGCGAA CTCCGGGACGCTCAGTAATG TGACGATAGC TGAAAACTGT ACGATAAACG GTACGCTGAG GGCGGAAAAAATCGTCGGGG ACATTGTAAA GGCGGCGAGC GCGGCTTTTC CGCGCCAGCG TGAAAGCAGTGTGGACTGGC CGTCAGGTAC CCGTACTGTC ACCGTGACCG ATGACCATCC TTTTGATCGCCAGATAGTGG TGCTTCCGCT GACGTTTCGC GGAAGTAAGC GTACTGTCAG CGGCAGGACAACGTATTCGA TGTGTTATCT GAAAGTACTG ATGAACGGTG CGGTGATTTA TGATGGCGCGGCGAACGAGG CGGTACAGGT GTTCTCCCGT ATTGTTGACA TGCCAGCGGG TCGGGGAAACGTGATCCTGA CGTTCACGCT TACGTCCACA CGGCATTCGG CAGATATTCC GCCGTATACGTTTGCCAGCG ATGTGCAGGT TATGGTGATT AAGAAACAGG CGCTGGGCAT CAGCGTGGTCTGAGTGTGTT ACAGAGGTTC GTCCGGGAAC GGGCGTTTTA TTATAAAACA GTGAGAGGTGAACGATGCGT AATGTGTGTA TTGCCGTTGC TGTCTTTGCC GCACTTGCGG TGACAGTCACTCCGGCCCGT GCGGAAGGTG GACATGGTAC GTTTACGGTG GGCTATTTTC AAGTGAAACCGGGTACATTG CCGTCGTTGT CGGGCGGGGA TACCGGTGTG AGTCATCTGA AAGGGATTAACGTGAAGTAC CGTTATGAGC TGACGGACAG TGTGGGGGTG ATGGCTTCCC TGGGGTTCGCCGCGTCGAAA AAGAGCAGCA CAGTGATGAC CGGGGAGGAT ACGTTTCACT ATGAGAGCCTGCGTGGACGT TATGTGAGCG TGATGGCCGG ACCGGTTTTA CAAATCAGTA AGCAGGTCAGTGCGTACGCC ATGGCCGGAG TGGCTCACAG TCGGTGGTCC GGCAGTACAA TGGATTACCGTAAGACGGAA ATCACTCCCG GGTATATGAA AGAGACGACC ACTGCCAGGG ACGAAAGTGCAATGCGGCAT ACCTCAGTGG CGTGGAGTGC AGGTATACAG ATTAATCCGG CAGCGTCCGTCGTTGTTGAT ATTGCTTATG AAGGCTCCGG CAGTGGCGAC TGGCGTACTG ACGGATTCATCGTTGGGGTC GGTTATAAAT TCTGATTAGC CAGGTAACAC AGTGTTATGA CAGCCCGCCGGAACCGGTGG GCTTTTTTGT GGGGTGAATA TGGCAGTAAA GATTTCAGGA GTCCTGAAAGACGGCACAGG AAAACCGGTA CAGAACTGCA CCATTCAGCT GAAAGCCAGA CGTAACAGCACCACGGTGGT GGTGAACACG GTGGGCTCAG AGAATCCGGA TGAAGCCGGG CGTTACAGCATGGATGTGGA GTACGGTCAG TACAGTGTCA TCCTGCAGGT TGACGGTTTT CCACCATCGCACGCCGGGAC CATCACCGTG TATGAAGATT CACAACCGGG GACGCTGAAT GATTTTCTCTGTGCCATGAC GGAGGATGAT GCCCGGCCGG AGGTGCTGCG TCGTCTTGAA CTGATGGTGGAAGAGGTGGC GCGTAACGCG TCCGTGGTGG CACAGAGTAC GGCAGACGCG AAGAAATCAGCCGGCGATGC CAGTGCATCA GCTGCTCAGG TCGCGGCCCT TGTGACTGAT GCAACTGACTCAGCACGCGC CGCCAGCACG TCCGCCGGAC AGGCTGCATC GTCAGCTCAG GAAGCGTCCTCCGGCGCAGA AGCGGCATCA GCAAAGGCCA CTGAAGCGGA AAAAAGTGCC GCAGCCGCAGAGTCCTCAAA AAACGCGGCG GCCACCAGTG CCGGTGCGGC GAAAACGTCA GAAACGAATGCTGCAGCGTC ACAACAATCA GCCGCCACGT CTGCCTCCAC CGCGGCCACG AAAGCGTCAGAGGCCGCCAC TTCAGCACGA GATGCGGTGG CCTCAAAAGA GGCAGCAAAA TCATCAGAAACGAACGCATC ATCAAGTGCC GGTCGTGCAG CTTCCTCGGC AACGGCGGCA GAAAATTCTGCCAGGGCGGC AAAAACGTCC GAGACGAATG CCAGGTCATC TGAAACAGCA GCGGAACGGAGCGCCTCTGC CGCGGCAGAC GCAAAAACAG CGGCGGCGGG GAGTGCGTCA ACGGCATCCACGAAGGCGAC AGAGGCTGCG GGAAGTGCGG TATCAGCATC GCAGAGCAAA AGTGCGGCAGAAGCGGCGGC AATACGTGCA AAAAATTCGG CAAAACGTGC AGAAGATATA GCTTCAGCTGTCGCGCTTGA GGATGCGGAC ACAACGAGAA AGGGGATAGT GCAGCTCAGC AGTGCAACCAACAGCACGTC TGAAACGCTT GCTGCAACGC CAAAGGCGGT TAAGGTGGTA ATGGATGAAACGAACAGAAA AGCCCACTGG ACAGTCCGGC ACTGACCGGA ACGCCAACAG CACCAACCGCGCTCAGGGGA ACAAACAATA CCCAGATTGC GAACACCGCT TTTGTACTGG CCGCGATTGCAGATGTTATC GACGCGTCAC CTGACGCACT GAATACGCTG AATGAACTGG CCGCAGCGCTCGGGAATGAT CCAGATTTTG CTACCACCAT GACTAACGCG CTTGCGGGTA AACAACCGAAGAATGCGACA CTGACGGCGC TGGCAGGGCT TTCCACGGCG AAAAATAAAT TACCGTATTTTGCGGAAAAT GATGCCGCCA GCCTGACTGA ACTGACTCAG GTTGGCAGGG ATATTCTGGCAAAAAATTCC GTTGCAGATG TTCTTGAATA CCTTGGGGCC GGTGAGAATT CGGCCTTTCCGGCAGGTGCG CCGATCCCGT GGCCATCAGA TATCGTTCCG TCTGGCTACG TCCTGATGCAGGGGCAGGCG TTTGACAAAT CAGCCTACCC AAAACTTGCT GTCGCGTATC CATCGGGTGTGCTTCCTGAT ATGCGAGGCT GGACAATCAA GGGGAAACCC GCCAGCGGTC GTGCTGTATTGTCTCAGGAA CAGGATGGAA TTAAGTCGCA CACCCACAGT GCCAGTGCAT CCGGTACGGATTTGGGGACG AAAACCACAT CGTCGTTTGA TTACGGGACG AAAACAACAG GCAGTTTCGATTACGGCACC AAATCGACGA ATAACACGGG GGCTCATGCT CACAGTCTGA GCGGTTCAACAGGGGCCGCG GGTGCTCATG CCCACACAAG TGGTTTAAGG ATGAACAGTT CTGGCTGGAGTCAGTATGGA ACAGCAACCA TTACAGGAAG TTTATCCACA GTTAAAGGAA CCAGCACACAGGGTATTGCT TATTTATCGA AAACGGACAG TCAGGGCAGC CACAGTCACT CATTGTCCGGTACAGCCGTG AGTGCCGGTG CACATGCGCA TACAGTTGGT ATTGGTGCGC ACCAGCATCCGGTTGTTATC GGTGCTCATG CCCATTCTTT CAGTATTGGT TCACACGGAC ACACCATCACCGTTAACGCT GCGGGTAACG CGGAAAACAC CGTCAAAAAC ATTGCATTTA ACTATATTGTGAGGCTTGCA TAATGGCATT CAGAATGAGT GAACAACCAC GGACCATAAA AATTTATAATCTGCTGGCCG GAACTAATGA ATTTATTGGT GAAGGTGACG CATATATTCC GCCTCATACCGGTCTGCCTG CAAACAGTAC CGATATTGCA CCGCCAGATA TTCCGGCTGG CTTTGTGGCTGTTTTCAACA GTGATGAGGC ATCGTGGCAT CTCGTTGAAG ACCATCGGGG TAAAACCGTCTATGACGTGG CTTCCGGCGA CGCGTTATTT ATTTCTGAAC TCGGTCCGTT ACCGGAAAATTTTACCTGGT TATCGCCGGG AGGGGAATAT CAGAAGTGGA ACGGCACAGC CTGGGTGAAGGATACGGAAG CAGAAAAACT GTTCCG Fragment 4 (positions 22350-27972 of phagelambda) GATCCGGGAG GCGGAAGAAA CAAAAAAAAG CCTGATGCAG GTAGCCAGTGAGCATATTGC GCCGCTTCAG GATGCTGCAG ATCTGGAAAT TGCAACGAAG GAAGAAACCTCGTTGCTGGA AGCCTGGAAG AAGTATCGGG TGTTGCTGAA CCGTGTTGAT ACATCAACTGCACCTGATAT TGAGTGGCCT GCTGTCCCTG TTATGGAGTA ATCGTTTTGT GATATGCCGCAGAAACGTTG TATGAAATAA CGTTCTGCGG TTAGTTAGTA TATTGTAAAG CTGAGTATTGGTTTATTTGG CGATTATTAT CTTCAGGAGA ATAATGGAAG TTCTATGACT CAATTGTTCATAGTGTTTAC ATCACCGCCA ATTGCTTTTA AGACTGAACG CATGAAATAT GGTTTTTCGTCATGTTTTGA GTCTGCTGTT GATATTTCTA AAGTCGGTTT TTTTTCTTCG TTTTCTCTAACTATTTTCCA TGAAATACAT TTTTGATTAT TATTTGAATC AATTCCAATT ACCTGAAGTCTTTCATCTAT AATTGGCATT GTATGTATTG GTTTATTGGA GTAGATGCTT GCTTTTCTGAGCCATAGCTC TGATATCCAA ATGAAGCCAT AGGCATTTGT TATTTTGGCT CTGTCAGCTGCATAACGCCA AAAAATATAT TTATCTGCTT GATCTTCAAA TGTTGTATTG ATTAAATCAATTGGATGGAA TTGTTTATCA TAAAAAATTA ATGTTTGAAT GTGATAACCG TCCTTTAAAAAAGTCGTTTC TGCAAGCTTG GCTGTATAGT CAACTAACTC TTCTGTCGAA GTGATATTTTTAGGCTTATC TACCAGTTTT AGACGCTCTT TAATATCTTC AGGAATTATT TTATTGTCATATTGTATCAT GCTAAATGAC AATTTGCTTA TGGAGTAATC TTTTAATTTT AAATAAGTTATTCTCCTGGC TTCATCAAAT AAAGAGTCGA ATGATGTTGG CGAAATCACA TCGTCACCCATTGGATTGTT TATTTGTATG CCAAGAGAGT TACAGCAGTT ATACATTCTG CCATAGATTATAGCTAAGGC ATGTAATAAT TCGTAATCTT TTAGCGTATT AGCGACCCAT CGTCTTTCTGATTTAATAAT AGATGATTCA GTTAAATATG AAGGTAATTT CTTTTGTGCA AGTCTGACTAACTTTTTTAT ACCAATGTTT AACATACTTT CATTTGTAAT AAACTCAATG TCATTTTCTTCAATGTAAGA TGAAATAAGA GTAGCCTTTG CCTCGCTATA CATTTCTAAA TCGCCTTGTTTTTCTATCGT ATTGCGAGAA TTTTTAGCCC AAGCCATTAA TGGATCATTT TTCCATTTTTCAATAACATT ATTGTTATAC CAAATGTCAT ATCCTATAAT CTGGTTTTTG TTTTTTTGAATAATAAATGT TACTGTTCTT GCGGTTTGGA GGAATTGATT CAAATTCAAG CGAAATAATTCAGGGTCAAA ATATGTATCA ATGCAGCATT TGAGCAAGTG CGATAAATCT TTAAGTCTTCTTTCCCATGG TTTTTTAGTC ATAAAACTCT CCATTTTGAT AGGTTGCATG CTAGATGCTGATATATTTTA GAGGTGATAA AATTAACTGC TTAACTGTCA ATGTAATACA AGTTGTTTGATCTTTGCAAT GATTCTTATC AGAAACCATA TAGTAAATTA GTTACACAGG AAATTTTTAATATTATTATT ATCATTCATT ATGTATTAAA ATTAGAGTTG TGGCTTGGCT CTGCTAACACGTTGCTCATA GGAGATATGG TAGAGCCGCA GACACGTCGT ATGCAGGAAC GTGCTGCGGCTGGCTGGTGA ACTTCCGATA GTGCGGGTGT TGAATGATTT CCAGTTGCTA CCGATTTTACATATTTTTTG CATGAGAGAA TTTGTACCAC CTCCCACCGA CCATCTATGA CTGTACGCCACTGTCCCTAG GACTGCTATG TGCCGGAGCG GACATTACAA ACGTCCTTCT CGGTGCATGCCACTGTTGCC AATGACCTGC CTAGGAATTG GTTAGCAAGT TACTACCGGA TTTTGTAAAAACAGCCCTCC TCATATAAAA AGTATTCGTT CACTTCCGAT AAGCGTCGTA ATTTTCTATCTTTCATCATA TTCTAGATCC CTCTGAAAAA ATCTTCCGAG TTTGCTAGGC ACTGATACATAACTCTTTTC CAATAATTGG GGAAGTCATT CAAATCTATA ATAGGTTTCA GATTTGCTTCAATAAATTCT GACTGTAGCT GCTGAAACGT TGCGGTTGAA CTATATTTCC TTATAACTTTTACGAAAGAG TTTCTTTGAG TAATCACTTC ACTCAAGTGC TTCCCTGCCT CCAAACGATACCTGTTAGCA ATATTTAATA GCTTGAAATG ATGAAGAGCT CTGTGTTTGT CTTCCTGCCTCCAGTTCGCC GGGCATTCAA CATAAAAACT GATAGCACCC GGAGTTCCGG AAACGAAATTTGCATATACC CATTGCTCAC GAAAAAAAAT GTCCTTGTCG ATATAGGGAT GAATCGCTTGGTGTACCTCA TCTACTGCGA AAACTTGACC TTTCTCTCCC ATATTGCAGT CGCGGCACGATGGAACTAAA TTAATAGGCA TCACCGAAAA TTCAGGATAA TGTGCAATAG GAAGAAAATGATCTATATTT TTTGTCTGTC CTATATCACC ACAAAATGGA CATTTTTCAC CTGATGAAACAAGCATGTCA TCGTAATATG TTCTAGCGGG TTTGTTTTTA TCTCGGAGAT TATTTTCATAAAGCTTTTCT AATTTAACCT TTGTCAGGTT ACCAACTACT AAGGTTGTAG GCTCAAGAGGGTGTGTCCTG TCGTAGGTAA ATAACTGACC TGTCGAGCTT AATATTCTAT ATTGTTGTTCTTTCTGCAAA AAAGTGGGGA AGTGAGTAAT GAAATTATTT CTAACATTTA TCTGCATCATACCTTCCGAG CATTTATTAA GCATTTCGCT ATAAGTTCTC GCTGGAAGAG GTAGTTTTTTCATTGTACTT TACCTTCATC TCTGTTCATT ATCATCGCTT TTAAAACGGT TCGACCTTCTAATCCTATCT GACCATTATA ATTTTTTAGA ATGGTTTCAT AAGAAAGCTC TGAATCAACGGACTGCGATA ATAAGTGGTG GTATCCAGAA TTTGTCACTT CAAGTAAAAA CACCTCACGAGTTAAAACAC CTAAGTTCTC ACCGAATGTC TCAATATCCG GACGGATAAT ATTTATTGCTTCTCTTGACC GTAGGACTTT CCACATGCAG GATTTTGGAA CCTCTTGCAG TACTACTGGGGAATGAGTTG CAATTATTGC TACACCATTG CGTGCATCGA GTAAGTCGCT TAATGTTCGTAAAAAAGCAG AGAGCAAAGG TGGATGCAGA TGAACCTCTG GTTCATCGAA TAAAACTAATGACTTTTCGC CAACGACATC TACTAATCTT GTGATAGTAA ATAAAACAAT TGCATGTCCAGAGCTCATTC GAAGCAGATA TTTCTGGATA TTGTCATAAA ACAATTTAGT GAATTTATCATCGTCCACTT GAATCTGTGG TTCATTACGT CTTAACTCTT CATATTTAGA AATGAGGCTGATGAGTTCCA TATTTGAAAA GTTTTCATCA CTACTTAGTT TTTTGATAGC TTCAAGCCAGAGTTGTCTTT TTCTATCTAC TCTCATACAA CCAATAAATG CTGAAATGAA TTCTAAGCGGAGATCGCCTA GTGATTTTAA ACTATTGCTG GCAGCATTCT TGAGTCCAAT ATAAAAGTATTGTGTACCTT TTGCTGGGTC AGGTTGTTCT TTAGGAGGAG TAAAAGGATC AAATGCACTAAACGAAACTG AAACAAGCGA TCGAAAATAT CCCTTTGGGA TTCTTGACTC GATAAGTCTATTATTTTCAG AGAAAAAATA TTCATTGTTT TCTGGGTTGG TGATTGCACC AATCATTCCATTCAAAATTG TTGTTTTACC ACACCCATTC CGCCCGATAA AAGCATGAAT GTTCGTGCTGGGCATAGAAT TAACCGTCAC CTCAAAAGGT ATAGTTAAAT CACTGAATCC GGGAGCACTTTTTCTATTAA ATGAAAAGTG GAAATCTGAC AATTCTGGCA AACCATTTAA CACACGTGCGAACTGTCCAT GAATTTCTGA AAGAGTTACC CCTCTAAGTA ATGAGGTGTT AAGGACGCTTTCATTTTCAA TGTCGGCTAA TCGATTTGGC CATACTACTA AATCCTGAAT AGCTTTAAGAAGGTTATGTT TAAAACCATC GCTTAATTTG CTGAGATTAA CATAGTAGTC AATGCTTTCACCTAAGGAAA AAAACATTTC AGGGAGTTGA CTGAATTTTT TATCTATTAA TGAATAAGTGCTTACTTCTT CTTTTTGACC TACAAAACCA ATTTTAACAT TTCCGATATC GCATTTTTCACCATGCTCAT CAAAGACAGT AAGATAAAAC ATTGTAACAA AGGAATAGTC ATTCCAACCATCTGCTCGTA GGAATGCCTT ATTTTTTTCT ACTGCAGGAA TATACCCGCC TCTTTCAATAACACTAAACT CCAACATATA GTAACCCTTA ATTTTATTAA AATAACCGCA ATTTATTTGGCGGCAACACA GGATCTCTCT TTTAAGTTAC TCTCTATTAC ATACGTTTTC CATCTAAAAATTAGTAGTAT TGAACTTAAC GGGGCATCGT ATTGTAGTTT TCCATATTTA GCTTTCTGCTTCCTTTTGGA TAACCCACTG TTATTCATGT TGCATGGTGC ACTGTTTATA CCAACGATATAGTCTATTAA TGCATATATA GTATCGCCGA ACGATTAGCT CTTCAGGCTT CTGAAGAAGCGTTTCAAGTA CTAATAAGCC GATAGATAGC CACGGACTTC GTAGCCATTT TTCATAAGTGTTAACTTCCG CTCCTCGCTC ATAACAGACA TTCACTACAG TTATGGCGGA AAGGTATGCATGCTGGGTGT GGGGAAGTCG TGAAAGAAAA GAAGTCAGCT GCGTCGTTTG ACATCACTGCTATCTTCTTA CTGGTTATGC AGGTCGTAGT GGGTGGCACA CAAAGCTTTG CACTGGATTGCGAGGCTTTG TGCTTCTCTG GAGTGCGACA GGTTTGATGA CAAAAAATTA GCGCAAGAAGACAAAAATCA CCTTGCGCTA ATGCTCTGTT ACAGGTCACT AATACCATCT AAGTAGTTGATTCATAGTGA CTGCATATGT TGTGTTTTAC AGTATTATGT AGTCTGTTTT TTATGCAAAATCTAATTTAA TATATTGATA TTTATATCAT TTTACGTTTC TCGTTCAGCT TTTTTATACTAAGTTGGCAT TATAAAAAAG CATTGCTTAT CAATTTGTTG CAACGAACAG GTCACTATCAGTCAAAATAA AATCATTATT TGATTTCAAT TTTGTCCCAC TCCCTGCCTC TGTCATCACGATACTGTGAT GCCATGGTGT CCGACTTATG CCCGAGAAGA TGTTGAGCAA ACTTATCGCTTATCTGCTTC TCATAGAGTC TTGCAGACAA ACTGCGCAAC TCGTGAAAGG TAGGCG Fragment 5(positions 27976-34499 of phage lambda) GATCCCCTTC GAAGGAAAGA CCTGATGCTTTTCGTGCGCG CATAAAATAC CTTGATACTG TGCCGGATGA AAGCGGTTCG CGACGAGTAGATGCAATTAT GGTTTCTCCG CCAAGAATCT CTTTGCATTT ATCAAGTGTT TCCTTCATTGATATTCCGAG AGCATCAATA TGCAATGCTG TTGGGATGGC AATTTTTACG CCTGTTTTGCTTTGCTCGAC ATAAAGATAT CCATCTACGA TATCAGACCA CTTCATTTCG CATAAATCACCAACTCGTTG CCCGGTAACA ACAGCCAGTT CCATTGCAAG TCTGAGCCAA CATGGTGATGATTCTGCTGC TTGATAAATT TTCAGGTATT CGTCAGCCGT AAGTCTTGAT CTCCTTACCTCTGATTTTGC TGCGCGAGTG GCAGCGACAT GGTTTGTTGT TATATGGCCT TCAGCTATTGCCTCTCGGAA TGCATCGCTC AGTGTTGATC TGATTAACTT GGCTGACGCC GCCTTGCCCTCGTCTATGTA TCCATTGAGC ATTGCCGCAA TTTCTTTTGT GGTGATGTCT TCAAGTGGAGCATCAGGCAG ACCCCTCCTT ATTGCTTTAA TTTTGCTCAT GTAATTTATG AGTGTCTTCTGCTTGATTCC TCTGCTGGCC AGGATTTTTT CGTAGCGATC AAGCCATGAA TGTAACGTAACGGAATTATC ACTGTTGATT CTCGCTGTCA GAGGCTTGTG TTTGTGTCCT GAAAATAACTCAATGTTGGC CTGTATAGCT TCAGTGATTG CGATTCGCCT GTCTCTGCCT AATCCAAACTCTTTACCCGT CCTTGGGTCC CTGTAGCAGT AATATCCATT GTTTCTTATA TAAAGGTTAGGGGGTAAATC CCGGCGCTCA TGACTTCGCC TTCTTCCCAT TTCTGATCCT CTTCAAAAGGCCACCTGTTA CTGGTCGATT TAAGTCAACC TTTACCGCTG ATTCGTGGAA CAGATACTCTCTTCCATCCT TAACCGGAGG TGGGAATATC CTGCATTCCC GAACCCATCG ACGAACTGTTTCAAGGCTTC TTGGACGTCG CTGGCGTGCG TTCCACTCCT GAAGTGTCAA GTACATCGCAAAGTCTCCGC AATTACACGC AAGAAAAAAC CGCCATCAGG CGGCTTGGTG TTCTTTCAGTTCTTCAATTC GAATATTGGT TACGTCTGCA TGTGCTATCT GCGCCCATAT CATCCAGTGGTCGTAGCAGT CGTTGATGTT CTCCGCTTCG ATAACTCTGT TGAATGGCTC TCCATTCCATTCTCCTGTGA CTCGGAAGTG CATTTATCAT CTCCATAAAA CAAAACCCGC CGTAGCGAGTTCAGATAAAA TAAATCCCCG CGAGTGCGAG GATTGTTATG TAATATTGGG TTTAATCATCTATATGTTTT GTACAGAGAG GGCAAGTATC GTTTCCACCG TACTCGTGAT AATAATTTTGCACGGTATCA GTCATTTCTC GCACATTGCA GAATGGGGAT TTGTCTTCAT TAGACTTATAAACCTTCATG GAATATTTGT ATGCCGACTC TATATCTATA CCTTCATCTA CATAAACACCTTCGTGATGT CTGCATGGAG ACAAGACACC GGATCTGCAC AACATTGATA ACGCCCAATCTTTTTGCTCA GACTCTAACT CATTGATACT CATTTATAAA CTCCTTGCAA TGTATGTCGTTTCAGCTAAA CGGTATCAGC AATGTTTATG TAAAGAAACA GTAAGATAAT ACTCAACCCGATGTTTGAGT ACGGTCATCA TCTGACACTA CAGACTCTGG CATCGCTGTG AAGACGACGCGAAATTCAGC ATTTTCACAA GCGTTATCTT TTACAAAACC GATCTCACTC TCCTTTGATGCGAATGCCAG CGTCAGACAT CATATGCAGA TACTCACCTG CATCCTGAAC CCATTGACCTCCAACCCCGT AATAGCGATG CGTAATGATG TCGATAGTTA CTAACGGGTC TTGTTCGATTAACTGCCGCA GAAACTCTTC CAGGTCACCA GTGCAGTGCT TGATAACAGG AGTCTTCCCAGGATGGCGAA CAACAAGAAA CTGGTTTCCG TCTTCACGGA CTTCGTTGCT TTCCAGTTTAGCAATACGCT TACTCCCATC CGAGATAACA CCTTCGTAAT ACTCACGCTG CTCGTTGAGTTTTGATTTTG CTGTTTCAAG CTCAACACGC AGTTTCCCTA CTGTTAGCGC AATATCCTCGTTCTCCTGGT CGCGGCGTTT GATGTATTGC TGGTTTCTTT CCCGTTCATC CAGCAGTTCCAGCACAATCG ATGGTGTTAC CAATTCATGG AAAAGGTCTG CGTCAAATCC CCAGTCGTCATGCATTGCCT GCTCTGCCGC TTCACGCAGT GCCTGAGAGT TAATTTCGCT CACTTCGAACCTCTCTGTTT ACTGATAAGT TCCAGATCCT CCTGGCAACT TGCACAAGTC CGACAACCCTGAACGACCAG GCGTCTTCGT TCATCTATCG GATCGCCACA CTCACAACAA TGAGTGGCAGATATAGCCTG GTGGTTCAGG CGGCGCATTT TTATTGCTGT GTTGCGCTGT AATTCTTCTATTTCTGATGC TGAATCAATG ATGTCTGCCA TCTTTCATTA ATCCCTGAAC TGTTGGTTAATACGCTTGAG GGTGAATGCG AATAATAAAA AAGGAGCCTG TAGCTCCCTG ATGATTTTGCTTTTCATGTT CATCGTTCCT TAAAGACGCC GTTTAACATG CCGATTGCCA GGCTTAAATGAGTCGGTGTG AATCCCATCA GCGTTACCGT TTCGCGGTGC TTCTTCAGTA CGCTACGGCAAATGTCATCG ACGTTTTTAT CCGGAAACTG CTGTCTGGCT TTTTTTGATT TCAGAATTAGCCTGACGGGC AATGCTGCGA AGGGCGTTTT CCTGCTGAGG TGTCATTGAA CAAGTCCCATGTCGGCAAGC ATAAGCACAC AGAATATGAA GCCCGCTGCC AGAAAAATGC ATTCCGTGGTTGTCATACCT GGTTTCTCTC ATCTGCTTCT GCTTTCGCCA CCATCATTTC CAGCTTTTGTGAAAGGGATG CGGCTAACGT ATGAAATTCT TCGTCTGTTT CTACTGGTAT TGGCACAAACCTGATTCCAA TTTGAGCAAG GCTATGTGCC ATCTCGATAC TCGTTCTTAA CTCAACAGAAGATGCTTTGT GCATACAGCC CCTCGTTTAT TATTTATCTC CTCAGCCAGC CGCTGTGCTTTCAGTGGATT TCGGATAACA GAAAGGCCGG GAAATACCCA GCCTCGCTTT GTAACGGAGTAGACGAAAGT GATTGCGCCT ACCCGGATAT TATCGTGAGG ATGCGTCATC GCCATTGCTCCCCAAATACA AAACCAATTT CAGCCAGTGC CTCGTCCATT TTTTCGATGA ACTCCGGCACGATCTCGTCA AAACTCGCCA TGTACTTTTC ATCCCGCTCA ATCACGACAT AATGCAGGCCTTCACGCTTC ATACGCGGGT CATAGTTGGC AAAGTACCAG GCATTTTTTC GCGTCACCCACATGCTGTAC TGCACCTGGG CCATGTAAGC TGACTTTATG GCCTCGAAAC CACCGAGCCGGAACTTCATG AAATCCCGGG AGGTAAACGG GCATTTCAGT TCAAGGCCGT TGCCGTCACTGCATAAACCA TCGGGAGAGC AGGCGGTACG CATACTTTCG TCGCGATAGA TGATCGGGGATTCAGTAACA TTCACGCCGG AAGTGAATTC AAACAGGGTT CTGGCGTCGT TCTCGTACTGTTTTCCCCAG GCCAGTGCTT TAGCGTTAAC TTCCGGAGCC ACACCGGTGC AAACCTCAGCAAGCAGGGTG TGGAAGTAGG ACATTTTCAT GTCAGGCCAC TTCTTTCCGG AGCGGGGTTTTGCTATCACG TTGTGAACTT CTGAAGCGGT GATGACGCCG AGCCGTAATT TGTGCCACGCATCATCCCCC TGTTCGACAG CTCTCACATC GATCCCGGTA CGCTGCAGGA TAATGTCCGGTGTCATGCTG CCACCTTCTG CTCTGCGGCT TTCTGTTTCA GGAATCCAAG AGCTTTTACTGCTTCGGCCT GTGTCAGTTC TGACGATGCA CGAATGTCGC GGCGAAATAT CTGGGAACAGAGCGGCAATA AGTCGTCATC CCATGTTTTA TCCAGGGCGA TCAGCAGAGT GTTAATCTCCTGCATGGTTT CATCGTTAAC CGGAGTGATG TCGCGTTCCG GCTGACGTTC TGCAGTGTATGCAGTATTTT CGACAATGCG CTCGGCTTCA TCCTTGTCAT AGATACCAGC AAATCCGAAGGCCAGACGGG CACACTGAAT CATGGCTTTA TGACGTAACA TCCGTTTGGG ATGCGACTGCCACGGCCCCG TGATTTCTCT GCCTTCGCGA GTTTTGAATG GTTCGCGGCG GCATTCATCCATCCATTCGG TAACGCAGAT CGGATGATTA CGGTCCTTGC GGTAAATCCG GCATGTACAGGATTCATTGT CCTGCTCAAA GTCCATGCCA TCAAACTGCT GGTTTTCATT GATGATGCGGGACCAGCCAT CAACGCCCAC CACCGGAACG ATGCCATTCT GCTTATCAGG AAAGGCGTAAATTTCTTTCG TCCACGGATT AAGGCCGTAC TGGTTGGCAA CGATCAGTAA TGCGATGAACTGCGCATCGC TGGCATCACC TTTAAATGCC GTCTGGCGAA GAGTGGTGAT CAGTTCCTGTGGGTCGACAG AATCCATGCC GACACGTTCA GCCAGCTTCC CAGCCAGCGT TGCGAGTGCAGTACTCATTC GTTTTATACC TCTGAATCAA TATCAACCTG GTGGTGAGCA ATGGTTTCAACCATGTACCG GATGTGTTCT GCCATGCGCT CCTGAAACTC AACATCGTCA TCAAACGCACGGGTAATGGA TTTTTTGCTG GCCCCGTGGC GTTGCAAATG ATCGATGCAT AGCGATTCAAACAGGTGCTG GGGCAGGCCT TTTTCCATGT CGTCTGCCAG TTCTGCCTCT TTCTCTTCACGGGCGAGCTG CTGGTAGTGA CGCGCCCAGC TCTGAGCCTC AAGACGATCC TGAATGTAATAAGCGTTCAT GGCTGAACTC CTGAAATAGC TGTGAAAATA TCGCCCGCGA AATGCCGGGCTGATTAGGAA AACAGGAAAG GGGGTTAGTG AATGCTTTTG CTTGATCTCA GTTTCAGTATTAATATCCAT TTTTTATAAG CGTCGACGGC TTCACGAAAC ATCTTTTCAT CGCCAATAAAAGTGGCGATA GTGAATTTAG TCTGGATAGC CATAAGTGTT TGATCCATTC TTTGGGACTCCTGGCTGATT AAGTATGTCG ATAAGGCGTT TCCATCCGTC ACGTAATTTA CGGGTGATTCGTTCAAGTAA AGATTCGGAA GGGCAGCCAG CAACAGGCCA CCCTGCAATG GCATATTGCATGGTGTGCTC CTTATTTATA CATAACGAAA AACGCCTCGA GTGAAGCGTT ATTGGTATGCGGTAAAACCG CACTCAGGCG GCCTTGATAG TCATATCATC TGAATCAAAT ATTCCTGATGTATCGATATC GGTAATTCTT ATTCCTTCGC TACCATCCAT TGGAGGCCAT CCTTCCTGACCATTTCCATC ATTCCAGTCG AACTCACACA CAACACCATA TGCATTTAAG TCGCTTGAAATTGCTATAAG CAGAGCATGT TGCGCCAGCA TGATTAATAC AGCATTTAAT ACAGAGCCGTGTTTATTGAG TCGGTATTCA GAGTCTGACC AGAAATTATT AATCTGGTGA AGTTTTTCCTCTGTCATTAC GTCATGGTCG ATTTCAATTT CTATTGATGC TTTCCAGTCG TAATCAATGATGTATTTTTT GATGTTTGAC ATCTGTTCAT ATCCTCACAG ATAAAAAATC GCCCTCACACTGGAGGGCAA AGAAGATTTC CAATAATCAG AACAAGTCGG CTCCTGTTTA GTTACGAGCGACATTGCTCC GTGTATTCAC TCGTTGGAAT GAATACACAG TGCAGTGTTT ATTCTGTTATTTATGCCAAA AATAAAGGCC ACTATCAGGC AGCTTTGTTG TTCTGTTTAC CAAGTTCTCTGGCAATCATT GCCGTCGTTC GTATTGCCCA TTTATCGACA TATTTCCCAT CTTCCATTACAGGAAACATT TCTTCAGGCT TAACCATGCA TTCCGATTGC AGCTTGCATC CATTGCATCGCTTGAATTGT CCACACCATT GATTTTTATC AATAGTCGTA GTCATACGGA TAGTCCTGGTATTGTTCCAT CACATCCTGA GGATGCTCTT CGAACTCTTC AAATTCTTCT TCCATATATCACCTTAAATA GTGGATTGCG GTAGTAAAGA TTGTGCCTGT CTTTTAACCA CATCAGGCTCGGTGGTTCTC GTGTACCCCT ACAGCGAGAA ATCGGATAAA CTATTACAAC CCCTACAGTTTGATGAGTAT AGAAATG Fragment 6 (positions 34503-41732 of phage lambda)GATCCACTCG TTATTCTCGG ACGAGTGTTC AGTAATGAAC CTCTGGAGAG AACCATGTATATGATCGTTA TCTGGGTTGG ACTTCTGCTT TTAAGCCCAG ATAACTGGCC TGAATATGTTAATGAGAGAA TCGGTATTCC TCATGTGTGG CATGTTTTCG TCTTTGCTCT TGCATTTTCGCTAGCAATTA ATGTGCATCG ATTATCAGCT ATTGCCAGCG CCAGATATAA GCGATTTAAGCTAAGAAAAC GCATTAAGAT GCAAAACGAT AAAGTGCGAT CAGTAATTCA AAACCTTACAGAAGAGCAAT CTATGGTTTT GTGCGCAGCC CTTAATGAAG GCAGGAAGTA TGTGGTTACATCAAAACAAT TCCCATACAT TAGTGAGTTG ATTGAGCTTG GTGTGTTGAA CAAAACTTTTTCCCGATGGA ATGGAAAGCA TATATTATTC CCTATTGAGG ATATTTACTG GACTGAATTAGTTGCCAGCT ATGATCCATA TAATATTGAG ATAAAGCCAA GGCCAATATC TAAGTAACTAGATAAGAGGA ATCGATTTTC CCTTAATTTT CTGGCGTCCA CTGCATGTTA TGCCGCGTTCGCCAGGCTTG CTGTACCATG TGCGCTGATT CTTGCGCTCA ATACGTTGCA GGTTGCTTTCAATCTGTTTG TGGTATTCAG CCAGCACTGT AAGGTCTATC GGATTTAGTG CGCTTTCTACTCGTGATTTC GGTTTGCGAT TCAGCGAGAG AATAGGGCGG TTAACTGGTT TTGCGCTTACCCCAACCAAC AGGGGATTTG CTGCTTTCCA TTGAGCCTGT TTCTCTGCGC GACGTTCGCGGCGGCGTGTT TGTGCATCCA TCTGGATTCT CCTGTCAGTT AGCTTTGGTG GTGTGTGGCAGTTGTAGTCC TGAACGAAAA CCCCCCGCGA TTGGCACATT GGCAGCTAAT CCGGAATCGCACTTACGGCC AATGCTTCGT TTCGTATCAC ACACCCCAAA GCCTTCTGCT TTGAATGCTGCCCTTCTTCA GGGCTTAATT TTTAAGAGCG TCACCTTCAT GGTGGTCAGT GCGTCCTGCTGATGTGCTCA GTATCACCGC CAGTGGTATT TATGTCAACA CCGCCAGAGA TAATTTATCACCGCAGATGG TTATCTGTAT GTTTTTTATA TGAATTTATT TTTTGCAGGG GGGCATTGTTTGGTAGGTGA GAGATCTGAA TTGCTATGTT TAGTGAGTTG TATCTATTTA TTTTTCAATAAATACAATTG GTTATGTGTT TTGGGGGCGA TCGTGAGGCA AAGAAAACCC GGCGCTGAGGCCGGGTTATT CTTGTTCTCT GGTCAAATTA TATAGTTGGA AAACAAGGAT GCATATATGAATGAACGATG CAGAGGCAAT GCCGATGGCG ATAGTGGGTA TCATGTAGCC GCTTATGCTGGAAAGAAGCA ATAACCCGCA GAAAAACAAA GCTCCAAGCT CAACAAAACT AAGGGCATAGACAATAACTA CCGATGTCAT ATACCCATAC TCTCTAATCT TGGCCAGTCG GCGCGTTCTGCTTCCGATTA GAAACGTCAA GGCAGCAATC AGGATTGCAA TCATGGTTCC TGCATATGATGACAATGTCG CCCCAAGACC ATCTCTATGA GCTGAAAAAG AAACACCAGG AATGTAGTGGCGGAAAAGGA GATAGCAAAT GCTTACGATA ACGTAAGGAA TTATTACTAT GTAAACACCAGGCATGATTC TGTTCCGCAT AATTACTCCT GATAATTAAT CCTTAACTTT GCCCACCTGCCTTTTAAAAC ATTCCAGTAT ATCACTTTTC ATTCTTGCGT AGCAATATGC CATCTCTTCAGCTATCTCAG CATTGGTGAC CTTGTTCAGA GGCGCTGAGA GATGGCCTTT TTCTGATAGATAATGTTCTG TTAAAATATC TCCGGCCTCA TCTTTTGCCC GCAGGCTAAT GTCTGAAAATTGAGGTGACG GGTTAAAAAT AATATCCTTG GCAACCTTTT TTATATCCCT TTTAAATTTTGGCTTAATGA CTATATCCAA TGAGTCAAAA AGCTCCCCTT CAATATCTGT TGCCCCTAAGACCTTTAATA TATCGCCAAA TACAGGTAGC TTGGCTTCTA CCTTCACCGT TGTTCGGCCGATGAAATGCA TATGCATAAC ATCGTCTTTG GTGGTTCCCC TCATCAGTGG CTCTATCTGAACGCGCTCTC CACTGCTTAA TGACATTCCT TTCCCGATTA AAAAATCTGT CAGATCGGATGTGGTCGGCC CGAAAACAGT TCTGGCAAAA CCAATGGTGT CGCCTTCAAC AAACAAAAAAGATGGGAATC CCAATGATTC GTCATCTGCG AGGCTGTTCT TAATATCTTC AACTGAAGCTTTAGAGCGAT TTATCTTCTG AACCAGACTC TTGTCATTTG TTTTGGTAAA GAGAAAAGTTTTTCCATCGA TTTTATGAAT ATACAAATAA TTGGAGCCAA CCTGCAGGTG ATGATTATCAGCCAGCAGAG AATTAAGGAA AACAGACAGG TTTATTGAGC GCTTATCTTT CCCTTTATTTTTGCTGCGGT AAGTCGCATA AAAACCATTC TTCATAATTC AATCCATTTA CTATGTTATGTTCTGAGGGG AGTGAAAATT CCCCTAATTC GATGAAGATT CTTGCTCAAT TGTTATCAGCTATGCGCCGA CCAGAACACC TTGCCGATCA GCCAAACGTC TCTTCAGGCC ACTGACTAGCGATAACTTTC CCCACAACGG AACAACTCTC ATTGCATGGG ATCATTGGGT ACTGTGGGTTTAGTGGTTGT AAAAACACCT GACCGCTATC CCTGATCAGT TTCTTGAAGG TAAACTCATCACCCCCAAGT CTGGCTATGC AGAAATCACC TGGCTCAACA GCCTGCTCAG GGTCAACGAGAATTAACATT CCGTCAGGAA AGCTTGGCTT GGAGCCTGTT GGTGCGGTCA TGGAATTACCTTCAACCTCA AGCCAGAATG CAGAATCACT GGCTTTTTTG GTTGTGCTTA CCCATCTCTCCGCATCACCT TTGGTAAAGG TTCTAAGCTT AGGTGAGAAC ATCCCTGCCT GAACATGAGAAAAAACAGGG TACTCATACT CACTTCTAAG TGACGGCTGC ATACTAACCG CTTCATACATCTCGTAGATT TCTCTGGCGA TTGAAGGGCT AAATTCTTCA ACGCTAACTT TGAGAATTTTTGTAAGCAAT GCGGCGTTAT AAGCATTTAA TGCATTGATG CCATTAAATA AAGCACCAACGCCTGACTGC CCCATCCCCA TCTTGTCTGC GACAGATTCC TGGGATAAGC CAAGTTCATTTTTCTTTTTT TCATAAATTG CTTTAAGGCG ACGTGCGTCC TCAAGCTGCT CTTGTGTTAATGGTTTCTTT TTTGTGCTCA TACGTTAAAT CTATCACCGC AAGGGATAAA TATCTAACACCGTGCGTGTT GACTATTTTA CCTCTGGCGG TGATAATGGT TGCATGTACT AAGGAGGTTGTATGGAACAA CGCATAACCC TGAAAGATTA TGCAATGCGC TTTGGGCAAA CCAAGACAGCTAAAGATCTC GGCGTATATC AAAGCGCGAT CAACAAGGCC ATTCATGCAG GCCGAAAGATTTTTTTAACT ATAAACGCTG ATGGAAGCGT TTATGCGGAA GAGGTAAAGC CCTTCCCGAGTAACAAAAAA ACAACAGCAT AAATAACCCC GCTCTTACAC ATTCCAGCCC TGAAAAAGGGCATCAAATTA AACCACACCT ATGGTGTATG CATTTATTTG CATACATTCA ATCAATTGTTATCTAAGGAA ATACTTACAT ATGGTTCGTG CAAACAAACG CAACGAGGCT CTACGAATCGAGAGTGCGTT GCTTAACAAA ATCGCAATGC TTGGAACTGA GAAGACAGCG GAAGCTGTGGGCGTTGATAA GTCGCAGATC AGCAGGTGGA AGAGGGACTG GATTCCAAAG TTCTCAATGCTGCTTGCTGT TCTTGAATGG GGGGTCGTTG ACGACGACAT GGCTCGATTG GCGCGACAAGTTGCTGCGAT TCTCACCAAT AAAAAACGCC CGGCGGCAAC CGAGCGTTCT GAACAAATCCAGATGGAGTT CTGAGGTCAT TACTGGATCT ATCAACAGGA GTCATTATGA CAAATACAGCAAAAATACTC AACTTCGGCA GAGGTAACTT TGCCGGACAG GAGCGTAATG TGGCAGATCTCGATGATGGT TACGCCAGAC TATCAAATAT GCTGCTTGAG GCTTATTCGG GCGCAGATCTGACCAAGCGA CAGTTTAAAG TGCTGCTTGC CATTCTGCGT AAAACCTATG GGTGGAATAAACCAATGGAC AGAATCACCG ATTCTCAACT TAGCGAGATT ACAAAGTTAC CTGTCAAACGGTGCAATGAA GCCAAGTTAG AACTCGTCAG AATGAATATT ATCAAGCAGC AAGGCGGCATGTTTGGACCA AATAAAAACA TCTCAGAATG GTGCATCCCT CAAAACGAGG GAAAATCCCCTAAAACGAGG GATAAAACAT CCCTCAAATT GGGGGATTGC TATCCCTCAA AACAGGGGGACACAAAAGAC ACTATTACAA AAGAAAAAAG AAAAGATTAT TCGTCAGAGA ATTCTGGCGAATCCTCTGAC CAGCCAGAAA ACGACCTTTC TGTGGTGAAA CCGGATGCTG CAATTCAGAGCGGCAGCAAG TGGGGGACAG CAGAAGACCT GACCGCCGCA GAGTGGATGT TTGACATGGTGAAGACTATC GCACCATCAG CCAGAAAACC GAATTTTGCT GGGTGGGCTA ACGATATCCGCCTGATGCGT GAACGTGACG GACGTAACCA CCGCGACATG TGTGTGCTGT TCCGCTGGGCATGCCAGGAC AACTTCTGGT CCGGTAACGT GCTGAGCCCG GCCAAACTCC GCGATAAGTGGACCCAACTC GAAATCAACC GTAACAAGCA ACAGGCAGGC GTGACAGCCA GCAAACCAAAACTCGACCTG ACAAACACAG ACTGGATTTA CGGGGTGGAT CTATGAAAAA CATCGCCGCACAGATGGTTA ACTTTGACCG TGAGCAGATG CGTCGGATCG CCAACAACAT GCCGGAACAGTACGACGAAA AGCCGCAGGT ACAGCAGGTA GCGCAGATCA TCAACGGTGT GTTCAGCCAGTTACTGGCAA CTTTCCCGGC GAGCCTGGCT AACCGTGACC AGAACGAAGT GAACGAAATCCGTCGCCAGT GGGTTCTGGC TTTTCGGGAA AACGGGATCA CCACGATGGA ACAGGTTAACGCAGGAATGC GCGTAGCCCG TCGGCAGAAT CGACCATTTC TGCCATCACC CGGGCAGTTTGTTGCATGGT GCCGGGAAGA AGCATCCGTT ACCGCCGGAC TGCCAAACGT CAGCGAGCTGGTTGATATGG TTTACGAGTA TTGCCGGAAG CGAGGCCTGT ATCCGGATGC GGAGTCTTATCCGTGGAAAT CAAACGCGCA CTACTGGCTG GTTACCAACC TGTATCAGAA CATGCGGGCCAATGCGCTTA CTGATGCGGA ATTACGCCGT AAGGCCGCAG ATGAGCTTGT CCATATGACTGCGAGAATTA ACCGTGGTGA GGCGATCCCT GAACCAGTAA AACAACTTCC TGTCATGGGCGGTAGACCTC TAAATCGTGC ACAGGCTCTG GCGAAGATCG CAGAAATCAA AGCTAAGTTCGGACTGAAAG GAGCAAGTGT ATGACGGGCA AAGAGGCAAT TATTCATTAC CTGGGGACGCATAATAGCTT CTGTGCGCCG GACGTTGCCG CGCTAACAGG CGCAACAGTA ACCAGCATAAATCAGGCCGC GGCTAAAATG GCACGGGCAG GTCTTCTGGT TATCGAAGGT AAGGTCTGGCGAACGGTGTA TTACCGGTTT GCTACCAGGG AAGAACGGGA AGGAAAGATG AGCACGAACCTGGTTTTTAA GGAGTGTCGC CAGAGTGCCG CGATGAAACG GGTATTGGCG GTATATGGAGTTAAAAGATG ACCATCTACA TTACTGAGCT AATAACAGGC CTGCTGGTAA TCGCAGGCCTTTTTATTTGG GGGAGAGGGA AGTCATGAAA AAACTAACCT TTGAAATTCG ATCTCCAGCACATCAGCAAA ACGCTATTCA CGCAGTACAG CAAATCCTTC CAGACCCAAC CAAACCAATCGTAGTAACCA TTCAGGAACG CAACCGCAGC TTAGACCAAA ACAGGAAGCT ATGGGCCTGCTTAGGTGACG TCTCTCGTCA GGTTGAATGG CATGGTCGCT GGCTGGATGC AGAAAGCTGGAAGTGTGTGT TTACCGCAGC ATTAAAGCAG CAGGATGTTG TTCCTAACCT TGCCGGGAATGGCTTTGTGG TAATAGGCCA GTCAACCAGC AGGATGCGTG TAGGCGAATT TGCGGAGCTATTAGAGCTTA TACAGGCATT CGGTACAGAG CGTGGCGTTA AGTGGTCAGA CGAAGCGAGACTGGCTCTGG AGTGGAAAGC GAGATGGGGA GACAGGGCTG CATGATAAAT GTCGTTAGTTTCTCCGGTGG CAGGACGTCA GCATATTTGC TCTGGCTAAT GGAGCAAAAG CGACGGGCAGGTAAAGACGT GCATTACGTT TTCATGGATA CAGGTTGTGA ACATCCAATG ACATATCGGTTTGTCAGGGA AGTTGTGAAG TTCTGGGATA TACCGCTCAC CGTATTGCAG GTTGATATCAACCCGGAGCT TGGACAGCCA AATGGTTATA CGGTATGGGA ACCAAAGGAT ATTCAGACGCGAATGCCTGT TCTGAAGCCA TTTATCGATA TGGTAAAGAA ATATGGCACT CCATACGTCGGCGGCGCGTT CTGCACTGAC AGATTAAAAC TCGTTCCCTT CACCAAATAC TGTGATGACCATTTCGGGCG AGGGAATTAC ACCACGTGGA TTGGCATCAG AGCTGATGAA CCGAAGCGGCTAAAGCCAAA GCCTGGAATC AGATATCTTG CTGAACTGTC AGACTTTGAG AAGGAAGATATCCTCGCATG GTGGAAGCAA CAACCATTCG ATTTGCAAAT ACCGGAACAT CTCGGTAACTGCATATTCTG CATTAAAAAA TCAACGCAAA AAATCGGACT TGCCTGCAAA GATGAGGAGGGATTGCAGCG TGTTTTTAAT GAGGTCATCA CGG Fragment 7 (positions 41736-48502of phage lambda) GATCCCATGT GCGTGACGGA CATCGGGAAA CGCCAAAGGA GATTATGTACCGAGGAAGAA TGTCGCTGGA CGGTATCGCG AAAATGTATT CAGAAAATGA TTATCAAGCCCTGTATCAGG ACATGGTACG AGCTAAAAGA TTCGATACCG GCTCTTGTTC TGAGTCATGCGAAATATTTG GAGGGCAGCT TGATTTCGAC TTCGGGAGGG AAGCTGCATG ATGCGATGTTATCGGTGCGG TGAATGCAAA GAAGATAACC GCTTCCGACC AAATCAACCT TACTGGAATCGATGGTGTCT CCGGTGTGAA AGAACACCAA CAGGGGTGTT ACCACTACCG CAGGAAAAGGAGGACGTGTG GCGAGACAGC GACGAAGTAT CACCGACATA ATCTGCGAAA ACTGCAAATACCTTCCAACG AAACGCACCA GAAATAAACC CAAGCCAATC CCAAAAGAAT CTGACGTAAAAACCTTCAAC TACACGGCTC ACCTGTGGGA TATCCGGTGG CTAAGACGTC GTGCGAGGAAAACAAGGTGA TTGACCAAAA TCGAAGTTAC GAACAAGAAA GCGTCGAGCG AGCTTTAACGTGCGCTAACT GCGGTCAGAA GCTGCATGTG CTGGAAGTTC ACGTGTGTGA GCACTGCTGCGCAGAACTGA TGAGCGATCC GAATAGCTCG ATGCACGAGG AAGAAGATGA TGGCTAAACCAGCGCGAAGA CGATGTAAAA ACGATGAATG CCGGGAATGG TTTCACCCTG CATTCGCTAATCAGTGGTGG TGCTCTCCAG AGTGTGGAAC CAAGATAGCA CTCGAACGAC GAAGTAAAGAACGCGAAAAA GCGGAAAAAG CAGCAGAGAA GAAACGACGA CGAGAGGAGC AGAAACAGAAAGATAAACTT AAGATTCGAA AACTCGCCTT AAAGCCCCGC AGTTACTGGA TTAAACAAGCCCAACAAGCC GTAAACGCCT TCATCAGAGA AAGAGACCGC GACTTACCAT GTATCTCGTGCGGAACGCTC ACGTCTGCTC AGTGGGATGC CGGACATTAC CGGACAACTG CTGCGGCACCTCAACTCCGA TTTAATGAAC GCAATATTCA CAAGCAATGC GTGGTGTGCA ACCAGCACAAAAGCGGAAAT CTCGTTCCGT ATCGCGTCGA ACTGATTAGC CGCATCGGGC AGGAAGCAGTAGACGAAATC GAATCAAACC ATAACCGCCA TCGCTGGACT ATCGAAGAGT GCAAGGCGATCAAGGCAGAG TACCAACAGA AACTCAAAGA CCTGCGAAAT AGCAGAAGTG AGGCCGCATGACGTTCTCAG TAAAAACCAT TCCAGACATG CTCGTTGAAA CATACGGAAA TCAGACAGAAGTAGCACGCA GACTGAAATG TAGTCGCGGT ACGGTCAGAA AATACGTTGA TGATAAAGACGGGAAAATGC ACGCCATCGT CAACGACGTT CTCATGGTTC ATCGCGGATG GAGTGAAAGAGATGCGCTAT TACGAAAAAA TTGATGGCAG CAAATACCGA AATATTTGGG TAGTTGGCGATCTGCACGGA TGCTACACGA ACCTGATGAA CAAACTGGAT ACGATTGGAT TCGACAACAAAAAAGACCTG CTTATCTCGG TGGGCGATTT GGTTGATCGT GGTGCAGAGA ACGTTGAATGCCTGGAATTA ATCACATTCC CCTGGTTCAG AGCTGTACGT GGAAACCATG AGCAAATGATGATTGATGGC TTATCAGAGC GTGGAAACGT TAATCACTGG CTGCTTAATG GCGGTGGCTGGTTCTTTAAT CTCGATTACG ACAAAGAAAT TCTGGCTAAA GCTCTTGCCC ATAAAGCAGATGAACTTCCG TTAATCATCG AACTGGTGAG CAAAGATAAA AAATATGTTA TCTGCCACGCCGATTATCCC TTTGACGAAT ACGAGTTTGG AAAGCCAGTT GATCATCAGC AGGTAATCTGGAACCGCGAA CGAATCAGCA ACTCACAAAA CGGGATCGTG AAAGAAATCA AAGGCGCGGACACGTTCATC TTTGGTCATA CGCCAGCAGT GAAACCACTC AAGTTTGCCA ACCAAATGTATATCGATACC GGCGCAGTGT TCTGCGGAAA CCTAACATTG ATTCAGGTAC AGGGAGAAGGCGCATGAGAC TCGAAAGCGT AGCTAAATTT CATTCGCCAA AAAGCCCGAT GATGAGCGACTCACCACGGG CCACGGCTTC TGACTCTCTT TCCGGTACTG ATGTGATGGC TGCTATGGGGATGGCGCAAT CACAAGCCGG ATTCGGTATG GCTGCATTCT GCGGTAAGCA CGAACTCAGCCAGAACGACA AACAAAAGGC TATCAACTAT CTGATGCAAT TTGCACACAA GGTATCGGGGAAATACCGTG GTGTGGCAAA GCTTGAAGGA AATACTAAGG CAAAGGTACT GCAAGTGCTCGCAACATTCG CTTATGCGGA TTATTGCCGT AGTGCCGCGA CGCCGGGGGC AAGATGCAGAGATTGCCATG GTACAGGCCG TGCGGTTGAT ATTGCCAAAA CAGAGCTGTG GGGGAGAGTTGTCGAGAAAG AGTGCGGAAG ATGCAAAGGC GTCGGCTATT CAAGGATGCC AGCAAGCGCAGCATATCGCG CTGTGACGAT GCTAATCCCA AACCTTACCC AACCCACCTG GTCACGCACTGTTAAGCCGC TGTATGACGC TCTGGTGGTG CAATGCCACA AAGAAGAGTC AATCGCAGACAACATTTTGA ATGCGGTCAC ACGTTAGCAG CATGATTGCC ACGGATGGCA ACATATTAACGGCATGATAT TGACTTATTG AATAAAATTG GGTAAATTTG ACTCAACGAT GGGTTAATTCGCTCGTTGTG GTAGTGAGAT GAAAAGAGGC GGCGCTTACT ACCGATTCCG CCTAGTTGGTCACTTCGACG TATCGTCTGG AACTCCAACC ATCGCAGGCA GAGAGGTCTG CAAAATGCAATCCCGAAACA GTTCGCAGGT AATAGTTAGA GCCTGCATAA CGGTTTCGGG ATTTTTTATATCTGCACAAC AGGTAAGAGC ATTGAGTCGA TAATCGTGAA GAGTCGGCGA GCCTGGTTAGCCAGTGCTCT TTCCGTTGTG CTGAATTAAG CGAATACCGG AAGCAGAACC GGATCACCAAATGCGTACAG GCGTCATCGC CGCCCAGCAA CAGCACAACC CAAACTGAGC CGTAGCCACTGTCTGTCCTG AATTCATTAG TAATAGTTAC GCTGCGGCCT TTTACACATG ACCTTCGTGAAAGCGGGTGG CAGGAGGTCG CGCTAACAAC CTCCTGCCGT TTTGCCCGTG CATATCGGTCACGAACAAAT CTGATTACTA AACACAGTAG CCTGGATTTG TTCTATCAGT AATCGACCTTATTCCTAATT AAATAGAGCA AATCCCCTTA TTGGGGGTAA GACATGAAGA TGCCAGAAAAACATGACCTG TTGGCCGCCA TTCTCGCGGC AAAGGAACAA GGCATCGGGG CAATCCTTGCGTTTGCAATG GCGTACCTTC GCGGCAGATA TAATGGCGGT GCGTTTACAA AAACAGTAATCGACGCAACG ATGTGCGCCA TTATCGCCTA GTTCATTCGT GACCTTCTCG ACTTCGCCGGACTAAGTAGC AATCTCGCTT ATATAACGAG CGTGTTTATC GGCTACATCG GTACTGACTCGATTGGTTCG CTTATCAAAC GCTTCGCTGC TAAAAAAGCC GGAGTAGAAG ATGGTAGAAATCAATAATCA ACGTAAGGCG TTCCTCGATA TGCTGGCGTG GTCGGAGGGA ACTGATAACGGACGTCAGAA AACCAGAAAT CATGGTTATG ACGTCATTGT AGGCGGAGAG CTATTTACTGATTACTCCGA TCACCCTCGC AAACTTGTCA CGCTAAACCC AAAACTCAAA TCAACAGGCGCCGGACGCTA CCAGCTTCTT TCCCGTTGGT GGGATGCCTA CCGCAAGCAG CTTGGCCTGAAAGACTTCTC TCCGAAAAGT CAGGACGCTG TGGCATTGCA GCAGATTAAG GAGCGTGGCGCTTTACCTAT GATTGATCGT GGTGATATCC GTCAGGCAAT CGACCGTTGC AGCAATATCTGGGCTTCACT GCCGGGCGCT GGTTATGGTC AGTTCGAGCA TAAGGCTGAC AGCCTGATTGCAAAATTCAA AGAAGCGGGC GGAACGGTCA GAGAGATTGA TGTATGAGCA GAGTCACCGCGATTATCTCC GCTCTGGTTA TCTGCATCAT CGTCTGCCTG TCATGGGCTG TTAATCATTACCGTGATAAC GCCATTACCT ACAAAGCCCA GCGCGACAAA AATGCCAGAG AACTGAAGCTGGCGAACGCG GCAATTACTG ACATGCAGAT GCGTCAGCGT GATGTTGCTG CGCTCGATGCAAAATACACG AAGGAGTTAG CTGATGCTAA AGCTGAAAAT GATGCTCTGC GTGATGATGTTGCCGCTGGT CGTCGTCGGT TGCACATCAA AGCAGTCTGT CAGTCAGTGC GTGAAGCCACCACCGCCTCC GGCGTGGATA ATGCAGCCTC CCCCCGACTG GCAGACACCG CTGAACGGGATTATTTCACC CTCAGAGAGA GGCTGATCAC TATGCAAAAA CAACTGGAAG GAACCCAGAAGTATATTAAT GAGCAGTGCA GATAGAGTTG CCCATATCGA TGGGCAACTC ATGCAATTATTGTGAGCAAT ACACACGCGC TTCCAGCGGA GTATAAATGC CTAAAGTAAT AAAACCGAGCAATCCATTTA CGAATGTTTG CTGGGTTTCT GTTTTAACAA CATTTTCTGC GCCGCCACAAATTTTGGCTG CATCGACAGT TTTCTTCTGC CCAATTCCAG AAACGAAGAA ATGATGGGTGATGGTTTCCT TTGGTGCTAC TGCTGCCGGT TTGTTTTGAA CAGTAAACGT CTGTTGAGCACATCCTGTAA TAAGCAGGGC CAGCGCAGTA GCGAGTAGCA TTTTTTTCAT GGTGTTATTCCCGATGCTTT TTGAAGTTCG CAGAATCGTA TGTGTAGAAA ATTAAACAAA CCCTAAACAATGAGTTGAAA TTTCATATTG TTAATATTTA TTAATGTATG TCAGGTGCGA TGAATCGTCATTGTATTCCC GGATTAACTA TGTCCACAGC CCTGACGGGG AACTTCTCTG CGGGAGTGTCCGGGAATAAT TAAAACGATG CACACAGGGT TTAGCGCGTA CACGTATTGC ATTATGCCAACGCCCCGGTG CTGACACGGA AGAAACCGGA CGTTATGATT TAGCGTGGAA AGATTTGTGTAGTGTTCTGA ATGCTCTCAG TAAATAGTAA TGAATTATCA AAGGTATAGT AATATCTTTTATGTTCATGG ATATTTGTAA CCCATCGGAA AACTCCTGCT TTAGCAAGAT TTTCCCTGTATTGCTGAAAT GTGATTTCTC TTGATTTCAA CCTATCATAG GACGTTTCTA TAAGATGCGTGTTTCTTGAG AATTTAACAT TTACAACCTT TTTAAGTCCT TTTATTAACA CGGTGTTATCGTTTTCTAAC ACGATGTGAA TATTATCTGT GGCTAGATAG TAAATATAAT GTGAGACGTTGTGACGTTTT AGTTCAGAAT AAAACAATTC ACAGTCTAAA TCTTTTCGCA CTTGATCGAATATTTCTTTA AAAATGGCAA CCTGAGCCAT TGGTAAAACC TTCCATGTGA TACGAGGGCGCGTAGTTTGC ATTATCGTTT TTATCGTTTC AATCTGGTCT GACCTCCTTG TGTTTTGTTGATGATTTATG TCAAATATTA GGAATGTTTT CACTTAATAG TATTGGTTGC GTAACAAAGTGCGGTCCTGC TGGCATTCTG GAGGGAAATA CAACCGACAG ATGTATGTAA GGCCAACGTGCTCAAATCTT CATACAGAAA GATTTGAAGT AATATTTTAA CCGCTAGATG AAGAGCAAGCGCATGGAGCG ACAAAATGAA TAAAGAACAA TCTGCTGATG ATCCCTCCGT GGATCTGATTCGTGTAAAAA ATATGCTTAA TAGCACCATT TCTATGAGTT ACCCTGATGT TGTAATTGCATGTATAGAAC ATAAGGTGTC TCTGGAAGCA TTCAGAGCAA TTGAGGCAGC GTTGGTGAAGCACGATAATA ATATGAAGGA TTATTCCCTG GTGGTTGACT GATCACCATA ACTGCTAATCATTCAAACTA TTTAGTCTGT GACAGAGCCA ACACGCAGTC TGTCACTGTC AGGAAAGTGGTAAAACTGCA ACTCAATTAC TGCAATGCCC TCGTAATTAA GTGAATTTAC AATATCGTCCTGTTCGGAGG GAAGAACGCG GGATGTTCAT TCTTCATCAC TTTTAATTGA TGTATATGCTCTCTTTTCTG ACGTTAGTCT CCGACGGCAG GCTTCAATGA CCCAGGCTGA GAAATTCCCGGACCCTTTTT GCTCAAGAGC GATGTTAATT TGTTCAATCA TTTGGTTAGG AAAGCGGATGTTGCGGGTTG TTGTTCTGCG GGTTCTGTTC TTCGTTGACA TGAGGTTGCC CCGTATTCAGTGTCGCTGAT TTGTATTGTC TGAAGTTGTT TTTACGTTAA GTTGATGCAG ATCAATTAATACGATACCTG CGTCATAATT GATTATTTGA CGTGGTTTGA TGGCCTCCAC GCACGTTGTGATATGTAGAT GATAATCATT ATCACTTTAC GGGTCCTTTC CGGTGATCCG ACAGGTTACGSequences of Enzyme Components Used

The tag may be left on to permit purification of a Cas-polynucleotidetarget complex, or removed by TEV cleavage.

>Spy_Cas9_wild-type: wild-type Cas9 fromStreptococcus pyogenes bearing C-terminal Strep (II) tagMDKKYSIGLDIGTNSVGWAVITDEYKVPSKKFKVLGNTDRHSIKKNLIGALLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENPINASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLTPNFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLRKQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNFDKNLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKTNRKVTVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKIIKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHPVENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVDHIVPQSFLKDDSIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKFDNLTKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLIREVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAVVGTALIKKYPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEVQTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVEKGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPEDNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDKPIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQSITGLYETRIDLSQLGGDGGSENLYFQGGSWSHPQFEKGGGSWSHPQFEK >Spy_Cas9_D10A: Cas9 nickase fromStreptococcus pyogenes bearing C-terminal Strep (II) tag MDKKYSIGL AIGTNSVGWAVITDEYKVPSKKEKVLGNTDRHSIKKNLIGALLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENPINASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLTPNFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLRKQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNEDKNLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKINRKVIVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKIIKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHPVENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVDHIVPQSFLKDDSIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKEDNLIKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLIREVKVITLKSKLVSDERKDFQFYKVREINNYHHAHDAYLNAVVGTALIKKYPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEVQTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVEKGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPEDNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDKPIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQSITGLYETRIDLSQLGGDGGSENLYFQGGSWSSHPQFEKGGGSWSHPQFEK >Spy_Cas9_H840A: Cas9 nickase fromStreptococcus pyogenes bearing C-terminal Strep (II) tagMDKKYSIGLDIGINSVGWAVITDEYKVPSKKEKVLGNTDRHSIKKNLIGALLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENPINASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLTPNFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLRKQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNFDKNLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKTNRKVTVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKIIKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHPVENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVD A IVPQSFLKDDSIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKFDNLTKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLIREVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAVVGTALIKKYPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEVQTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVEKGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPEDNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDKPIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQSITGLYETRIDLSQLGGDGGSENLYFQGGSWSHPQFEKGGGSWSHPQFEK >Spy_Cas9_D10A_H840A: dead Cas9(‘dCas9’) from Streptococcus pyogenes bearing C- terminal Strep (II) tagPurified as ONLP11836. MDKKYSIGL AIGTNSVGWAVITDEYKVPSKKFKVLGNTDRHSIKKNLIGALLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENPINASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLIPNFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLRKQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNFDKNLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKTNRKVTVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKIIKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHPVENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVD A IVPQSFLKDDSIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKFDNLTKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLIREVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAVVGTALIKKYPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEVQTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVEKGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPEDNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDKPIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQSITGLYETRIDLSQLGGDGGSENLYFQGGSWSHPQFEKGGGSWSHPQFEKSK007 Adapter Comprises the Below Three Sequences Hybridised Together

/5SpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3//iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3//iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3/ /iSpC3//iSpC3/ /iSpC3/ /iSpC3/ G G C G T C T G C T T G G G T G T T T A A C C T T T TT T T T T T /iSp18/ /iSp18/ /iSp18/ /iSp18/ A A T G T A C T T C G T T C A G TT A C G T A T T G C T/5Phos/ G C A A T A C G T A A C T G A A C G A A G T /iBNA-A/ / iBNA-meC//iBNA-A/ /iBNA-T/ /iBNA-T/ T T T G A G G C G A G C G G T C A A/5BNA-G/ /iBNA-G/ /iBNA-T/ /iBNA-T/ /iBNA-A/ A A C A C C C A A G C A G A C GC C T T Sequence SK43 /5//CholTEG/TTGACCGCTCGCCTC

Example 4

This Example describes a method for detection of a fragment containing aspecific 20 nt target DNA polynucleotide sequence (“target”) from amixture by direct detection of a target/probe complex, wherein thetarget DNA contacts CRISPR-Cas probe. In this Example, the “target” ispositively identified by the unique signal given by the target/probecomplex interacting with the Nanopore. In this case the pore is only bigenough to admit a single strand of DNA (FIG. 14).

Materials and Methods

A 3.6 kb length of lambda DNA which was end repaired and dA tailed atboth ends was ligated to SK007 adapter without helicase (ONLA16389,top+ONLA19936, bottom+ONLA19750, blocker). This was then purified usingSPRI beads as follows: 0.4 volume equivalents of AMPure XP SPRI magneticbeads (Beckman Coulter) were added to the mixture and the resultantmixture agitated for 5 min at 21° C. The magnetic beads were pelletedusing a magnetic separator, the supernatant aspirated, and 100 μl of 50mM Tris-Cl, 2.5 M NaCl, 20% PEG 8,000 (pH 7.5 at 25° C.) added to thebeads while still on the rack, turning the pellet through 360° to washthe pellet on the rack. The beads were immediately pelleted once moreand the supernatant aspirated, after which the tube was removed from therack and 45 μl of a buffer containing of 25 mM Tris-Cl, 20 mM NaCl (pH7.5 at 25° C.) was added to the beads to elute the DNA by incubation for5 min at 21° C. The beads were pelleted using the magnetic separator,and the eluate retained. This is the “double-Y 3.6 kb”.

CRISPR RNA (“crRNA”) AR148 which has a sequence targeting a region the3.6 kb lambda used previously, was hybridised with tracrRNA by annealingto 40 μM “Alt-R™” tracrRNA (purchased from IDT) in 10 mM Tris-Cl (pH8.0), 1 mM EDTA, 100 mM NaCl from 65° C. to 25° C. at 1.0° C. perminute, resulting in a complex known as a “guide RNA”. CRISPR-dCas9complexes were formed by incubating 100 nM “guide RNA” with 100 nM dCas9(ONLP11836) in Cas9 binding buffer (20 mM HEPES-NaOH, 100 mM NaCl, 5 mMMgCl2, 0.1 mM EDTA, pH 6.5 at 25° C.) for 10 minutes at 21° C., yielding100 nM of “CRISPR-dCas9 complex”.

0.5 μg of double-Y 3.6 kb was incubated with 50 μL of CRISPR-dCas9complex for at least 10 minutes at 20° C. To this was then added 65 μLof 2×c17 buffer (1M KCl, 50 mM HEPES, pH8), 12.5 μL of ELB and di waterto make the final volume up to 150 μL. This is the “chip sample”.

Electrical measurements were acquired from single CsgG nanoporesinserted in block co-polymer in buffer at 37° C. (25 mM HEPES-KOH, 150mM potassium ferrocyanide (II), 150 mM potassium ferricyanide (III), pH8.0). After achieving a single pore inserted in the block co-polymer,buffer (2 mL, 25 mM HEPES-KOH, 150 mM potassium ferrocyanide (II), 150mM potassium ferricyanide (III), pH 8.0) was flowed through the systemto remove any excess CsgG nanopores. All subsequent steps were performedat 34° C. The cis compartment was equilibrated with 500 μl of 25 mMHEPES (pH 8.0), 500 mM KCl (known as “c17”), with 10 mins between eachwash. 150 μl of chip sample was then added to the chip and data recordedat 100 mV at 34° C.

Results

When a CRISPR-dCas9 complex is not present, or when the CRISPR-dCas9complex does not have a crRNA sequence that is present in the double-Y3.6 kb, the signal obtained is characteristic of events at 60-80 pA thattypically last <0.5 s. FIGS. 33 and 34 show double-Y 3.6 kb without aCRISPR-dCas9 complex bound to it translocating through the pore.

When CRISPR-dCas9 complex is present but double-Y 3.6 kb is not, thereare no events observed.

When a double-Y 3.6 kb is bound to a CRISPR-dCas9 complex which has acrRNA sequence that is found in the double-Y 3.6 kb as described above,the signal is dominated by long blocks at ˜60 pA. These blocks typicallylast for >>10 s. Sometimes these events spontaneously return to the openpore current. These events have the same characteristic profile as thosedescribed above but have a new long static level in between the twoY-adapters. FIG. 14, FIG. 35 and FIG. 36 show the DNA translocatingthrough the pore until the CRISPR-dCas9 complex reaches the pore, atwhich point the double-Y 3.6 kb pauses until the CRISPR-dCas9 complex isdisplaced by the force of the pore acting on it, at which point thedouble-Y 3.6 kb continues to translocate.

Example 5

This Example describes a method for detection of a fragment containing aspecific 20 nucleotide target DNA polynucleotide sequence (“target”)from a mixture by direct detection of a target/probe complex, whereinthe target DNA contacts CRISPR-Cas probe. In this example, the “target”is positively identified by the unique signal given by the target/probecomplex interacting with the nanopore. In this case the pore is bigenough to admit double stranded DNA with the probe attached (see FIG.12).

Materials and Methods

A 3.6 kb length of lambda DNA was prepared and purified. This is the 3.6kb.

CRISPR RNA (“crRNA”) AR148 which has a sequence targeting a region the3.6 kb, was hybridised with tracrRNA by annealing to 40 μM “Alt-R™”tracrRNA (purchased from IDT) in 10 mM Tris-Cl (pH 8.0), 1 mM EDTA, 100mM NaCl from 65° C. to 25° C. at 1.0° C. per minute, resulting in acomplex known as a “guide RNA”. CRISPR-dCas9 complexes were formed byincubating 200 nM “guide RNA” with 200 nM dCas9 (ONLP11836) in Cas9binding buffer (20 mM HEPES-NaOH, 100 mM NaCl, 5 mM MgCl₂, 0.1 mM EDTA,pH 6.5 at 25° C.), for 10 minutes at 21° C., yielding 200 nM ofCRISPR-dCas9 complex.

0.5 μg of 3.6 kb was incubated with 25 μL of CRISPR-dCas9 complex for atleast 10 minutes at 20° C. To this was then added 25 μL of 2×1M buffer(2M KCl, 50 mM HEPES, pH8). This is the chip sample.

Electrical measurements were acquired from a single 15 nm diameter SiNALD pore formed by dielectric breakdown (but any pore with a diameterof >10 nM could have been used, for example solid state, protein, DNAorigami or any other material). The cis and trans were at 1M KCl whilethe voltage was varied. After a period of pore characterisation with nosample, the volume of the cis compartment was replaced with the chipsample and measurements carried out at different voltages at 20° C.

Results

When a CRISPR-dCas9 complex is not present, or when the CRISPR-dCas9complex does not have a crRNA sequence that is complementary to a DNAsequence in the 3.6 kb, the signal obtained is of a short lived currentdeflection as the 3.6 kb passes through the pore (FIG. 37). When a 3.6kb is bound to a CRISPR-dCas9 complex which has a crRNA sequence that iscomplementary to a DNA sequence found in the 3.6 kb, as described above,the signal now has an additional sublevel that represents theCRISPR-dCas9 complex passing through the pore (FIG. 38). Where multipleCRISPR-dCas9 complexes are bound to the DNA, each complex causes aseparate deflection to the current (FIG. 39). When the dCas is modifiedor decorated the signal changes as each complex passes through the pore(FIG. 40). The changes in signal positions of the current deflectionscaused by the complexes can be used to provide information about thepolynucleotide (e.g. DNA).

Sequence information AR148 AltR-CCGACCACGCCAGCAUAUCG-AltR ONLA16389/5SpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3/ /iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3/ /iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3//iSpC3/ /iSpC3/GGCGTCTGCTTGGGTGTTTAACCTTTTTTTTTT/iSp18//iSp18//iSp18//iSp18/AATGTACTTCGTTCAGTTACGTATTGCT ONLA19936/5Phos/GCAATACGTAACTGAACGAAGT/iBNA-A//iBNA-MeC//iBNA-A//iBNA-T//iBNA-T/TTTGAGGCGAGCGGTCAA ONLA19756/5BNA-G//iBNA-G//iBNA-T//iBNA-T//iBNA-A/AACACCCAAGCAGACGCCTT AltR tracrPurchased from IDT Tether/5chol-TEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTC 3.6kbGCCATCAGATTGTGTTTGTTAGTCGCTGCCATCAGATTGTGTTTGTTAGTCGCTTTTTTTTTTTGGAATTTTTTTTTTGGAATTTTTTTTTTGCGCTAACAACCTCCTGCCGTTTTGCCCGTGCATATCGGTCACGAACAAATCTGATTACTAAACACAGTAGCCTGGATTTGTTCTATCAGTAATCGACCTTATTCCTAATTAAATAGAGCAAATCCCCTTATTGGGGGTAAGACATGAAGATGCCAGAAAAACATGACCTGTTGGCCGCCATTCTCGCGGCAAAGGAACAAGGCATCGGGGCAATCCTTGCGTTTGCAATGGCGTACCTTCGCGGCAGATATAATGGCGGTGCGTTTACAAAAACAGTAATCGACGCAACGATGTGCGCCATTATCGCCTAGTTCATTCGTGACCTTCTCGACTTCGCCGGACTAAGTAGCAATCTCGCTTATATAACGAGCGTGTTTATCGGCTACATCGGTACTGACTCGATTGGTTCGCTTATCAAACGCTTCGCTGCTAAAAAAGCCGGAGTAGAAGATGGTAGAAATCAATAATCAACGTAAGGCGTTCCTCGATATGCTGGCGTGGTCGGAGGGAACTGATAACGGACGTCAGAAAACCAGAAATCATGGTTATGACGTCATTGTAGGCGGAGAGCTATTTACTGATTACTCCGATCACCCTCGCAAACTTGTCACGCTAAACCCAAAACTCAAATCAACAGGCGCCGGACGCTACCAGCTTCTTTCCCGTTGGTGGGATGCCTACCGCAAGCAGCTTGGCCTGAAAGACTTCTCTCCGAAAAGTCAGGACGCTGTGGCATTGCAGCAGATTAAGGAGCGTGGCGCTTTACCTATGATTGATCGTGGTGATATCCGTCAGGCAATCGACCGTTGCAGCAATATCTGGGCTTCACTGCCGGGCGCTGGTTATGGTCAGTTCGAGCATAAGGCTGACAGCCTGATTGCAAAATTCAAAGAAGCGGGCGGAACGGTCAGAGAGATTGATGTATGAGCAGAGTCACCGCGATTATCTCCGCTCTGGTTATCTGCATCATCGTCTGCCTGTCATGGGCTGTTAATCATTACCGTGATAACGCCATTACCTACAAAGCCCAGCGCGACAAAAATGCCAGAGAACTGAAGCTGGCGAACGCGGCAATTACTGACATGCAGATGCGTCAGCGTGATGTTGCTGCGCTCGATGCAAAATACACGAAGGAGTTAGCTGATGCTAAAGCTGAAAATGATGCTCTGCGTGATGATGTTGCCGCTGGTCGTCGTCGGTTGCACATCAAAGCAGTCTGTCAGTCAGTGCGTGAAGCCACCACCGCCTCCGGCGTGGATAATGCAGCCTCCCCCCGACTGGCAGACACCGCTGAACGGGATTATTTCACCCTCAGAGAGAGGCTGATCACTATGCAAAAACAACTGGAAGGAACCCAGAAGTATATTAATGAGCAGTGCAGATAGAGTTGCCCATATCGATGGGCAACTCATGCAATTATTGTGAGCAATACACACGCGCTTCCAGCGGAGTATAAATGCCTAAAGTAATAAAACCGAGCAATCCATTTACGAATGTTTGCTGGGTTTCTGTTTTAACAACATTTTCTGCGCCGCCACAAATTTTGGCTGCATCGACAGTTTTCTTCTGCCCAATTCCAGAAACGAAGAAATGATGGGTGATGGTTTCCTTTGGTGCTACTGCTGCCGGTTTGTTTTGAACAGTAAACGTCTGTTGAGCACATCCTGTAATAAGCAGGGCCAGCGCAGTAGCGAGTAGCATTTTTTTCATGGTGTTATTCCCGATGCTTTTTGAAGTTCGCAGAATCGTATGTGTAGAAAATTAAACAAACCCTAAACAATGAGTTGAAATTTCATATTGTTAATATTTATTAATGTATGTCAGGTGCGATGAATCGTCATTGTATTCCCGGATTAACTATGTCCACAGCCCTGACGGGGAACTTCTCTGCGGGAGTGTCCGGGAATAATTAAAACGATGCACACAGGGTTTAGCGCGTACACGTATTGCATTATGCCAACGCCCCGGTGCTGACACGGAAGAAACCGGACGTTATGATTTAGCGTGGAAAGATTTGTGTAGTGTTCTGAATGCTCTCAGTAAATAGTAATGAATTATCAAAGGTATAGTAATATCTTTTATGTTCATGGATATTTGTAACCCATCGGAAAACTCCTGCTTTAGCAAGATTTTCCCTGTATTGCTGAAATGTGATTTCTCTTGATTTCAACCTATCATAGGACGTTTCTATAAGATGCGTGTTTCTTGAGAATTTAACATTTACAACCTTTTTAAGTCCTTTTATTAACACGGTGTTATCGTTTTCTAACACGATGTGAATATTATCTGTGGCTAGATAGTAAATATAATGTGAGACGTTGTGACGTTTTAGTTCAGAATAAAACAATTCACAGTCTAAATCTTTTCGCACTTGATCGAATATTTCTTTAAAAATGGCAACCTGAGCCATTGGTAAAACCTTCCATGTGATACGAGGGCGCGTAGTTTGCATTATCGTTTTTATCGTTTCAATCTGGTCTGACCTCCTTGTGTTTTGTTGATGATTTATGTCAAATATTAGGAATGTTTTCACTTAATAGTATTGGTTGCGTAACAAAGTGCGGTCCTGCTGGCATTCTGGAGGGAAATACAACCGACAGATGTATGTAAGGCCAACGTGCTCAAATCTTCATACAGAAAGATTTGAAGTAATATTTTAACCGCTAGATGAAGAGCAAGCGCATGGAGCGACAAAATGAATAAAGAACAATCTGCTGATGATCCCTCCGTGGATCTGATTCGTGTAAAAAATATGCTTAATAGCACCATTTCTATGAGTTACCCTGATGTTGTAATTGCATGTATAGAACATAAGGTGTCTCTGGAAGCATTCAGAGCAATTGAGGCAGCGTTGGTGAAGCACGATAATAATATGAAGGATTATTCCCTGGTGGTTGACTGATCACCATAACTGCTAATCATTCAAACTATTTAGTCTGTGACAGAGCCAACACGCAGTCTGTCACTGTCAGGAAAGTGGTAAAACTGCAACTCAATTACTGCAATGCCCTCGTAATTAAGTGAATTTACAATATCGTCCTGTTCGGAGGGAAGAACGCGGGATGTTCATTCTTCATCACTTTTAATTGATGTATATGCTCTCTTTTCTGACGTTAGTCTCCGACGGCAGGCTTCAATGACCCAGGCTGAGAAATTCCCGGACCCTTTTTGCTCAAGAGCGATGTTAATTTGTTCAATCATTTGGTTAGGAAAGCGGATGTTGCGGGTTGTTGTTCTGCGGGTTCTGTTCTTCGTTGACATGAGGTTGCCCCGTATTCAGTGTCGCTGATTTGTATTGTCTGAAGTTGTTTTTACGTTAAGTTGATGCAGATCAATTAATACGATACCTGCGTCATAATTGATTATTTGACGTGGTTTGATGGCCTCCACGCACGTTGTGATATGTAGATGATAATCATTATCACTTTACGGGTCCTTTCCGGTGAAAAAAAAGGTACCAAAAAAAACATCGTCGTGAGTAGTGAACCGTAAGC

Example 6

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing followingthe enrichment of the target molecule. In this Example, the target DNAmolecule is identified primarily by its sequence. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the dCas9 molecule. The dCas9 binds preferably to the targetmolecule by means of a crRNA directed against the ribosomal 16S (rrs)genes of Escherichia coli. ‘Off-target’ effects are reduced by applyinga thermal and salt stress to the bound dCas9 protein, coupled with aSPRI purification step to remove excess, unbound dCas9 before subsequentpurification on a capture bead surface. The target DNA molecule isadapted for nanopore sequencing, and the dCas9 remains bound to itstarget until displaced by the enzyme loaded on the adapter.

The dCas9 carries a tracrRNA molecule bearing a 5′ DNA extension(sequence a of FIG. 41) that enables capture of the target molecule on abead-capture oligonucleotide conjugate that bears a DNA sequencecomplementary to this extension (sequence a′ of FIG. 41). In thisExample, the capture oligonucleotide is linked to the bead via a biotinmoiety. In this Example, the non-target DNA is washed away, and targetmolecules remain bound to the bead. The target molecule is then adaptedfor nanopore sequencing by ligation to either or both of its free,dA-tailed ends, while the dCas9-target molecule is bound to the bead.The entire bead-target-RNP assembly is then delivered to a flowcell forsequencing. The assembly is brought to the wells of the flowcell by theapplication of a magnetic field placed underneath the flowcell, or canbe allowed to settle by gravity. Sequencing is initiated by flowing anoligonucleotide cholesterol tether, which hybridizes to the adaptorends, over the beads, which tethers the beads to the membrane.Alternatively, the cholesterol tether can be introduced into themembrane during a ‘flush’ step, before the bead-target conjugate isadded to the flowcell.

Methods

An E. coli whole-genome library, ONLA18816 (NCBI Reference Sequence: NC000913.3), was prepared by random fragmentation of E. colihigh-molecular weight genomic DNA to a median size of ˜5.9 kb using aCovaris gTube following the manufacturer's instructions. This librarywas then end-repaired and dA-tailed using an NEB Ultra II kit, per themanufacturer's instructions. Following end-repair and dA-tailing, thefragmented genomic DNA was subjected to 0.4×SPRI purification and elutedfrom the SPRI beads in 0.1×TE.

200 nM DNA-extended tracrRNA (AR363) was added to a buffer containing 25mM HEPES-NaOH (pH 8.0), 150 mM NaCl and 1 mM MgCl₂ (known as dCas9binding buffer). The tracrRNA was heated to 90° C. for 2 min andsnap-cooled on wet ice, after which 100 nM dCas9 (ONLP12326) was addedand the reaction incubated for 10 min at room temperature (˜21° C.). 250nM crRNA (AR400) was then added to the reaction and incubated for afurther 10 min at room temperature (˜21° C.). The final volume was 50μL. This mixture was known as ribonucleotide-protein complexes (RNPs).

To form dCas9-target complexes, 500 ng (˜1.2 μL) of the genomic DNA fromabove (ONLA18816) was added to the RNPs and incubated for 20 min at roomtemperature. The mixture was then incubated at 55° C. for 5 min toremove dCas9 not bound to its intended target. The mixture was subjectedto 1×SPRI purification as follows: 51 μL AMPure XP beads were added tothe mixture, mixed by gentle resuspension, and incubated for 10 min atroom temperature. The beads were pelleted using a magnetic separator,and washed twice with ˜250 of a buffer comprising 50 mM Tris-Cl (pH 8.0at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted by incubating theSPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0), 40mM KCl for 5 min. The beads were pelleted once more and the supernatant,known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) wereincubated with 2.5 of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide wasremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

dCas9-bound target molecules were bound to capture beads by incubating12.5 μL of SPRI eluate with 10 μg capture beads (1 μL) and 65 μLDynabeads kilobaseBINDER Binding Solution (Thermo Scientific Cat.#60101) for 20 min with agitation. The beads were subsequently washedthree times with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.),150 mM NaCl, 1 mM EDTA, and once with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 20 mM NaCl. Following this step, the beads werepelleted and the supernatant removed. This sample was known as‘bead-target complex’.

Enzyme-loaded adaptors (tube ‘AMX 1D’) from Oxford NanoporeTechnologies' 1D Sequencing Kit by Ligation (SQK-LSK108) were ligated tothe bead-target complex by resuspending the pelleted beads from abovewith a ligation mix comprising 12.5 μL 2×LAQA1 buffer (a gift from NewEngland Biolabs, Inc.), 7 μL nuclease-free water, 5 μL AMX 1D (part ofSQK-LSK108), and 0.5 μL T4 DNA Ligase (NEB Cat. #M0202). The beads wereincubated in the ligation mix with agitation for 10 min, pelleted, andwashed once with ˜125 μL of a buffer containing 50 mM Tris-Cl (pH 8.0 at4° C.), 150 mM NaCl, 1 mM EDTA to remove free, unligated adapter.Following the wash, the beads were pelleted once more, and resuspendedin 50 μL of RBF (a component of SQK-LSK108), diluted to 1×according tothe manufacturer's instructions. This mixture was known as the loadingsample.

FIG. 41 shows the expected appearance of thedCas9-crRNA-tracrRNA-target-bead conjugate, also known here as theloading sample.

An Oxford Nanopore MinION flowcell was primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The entire 50 μL of the loading samplewas pipetted dropwise into the SpotON port and the fluid allowed to wickinto the flowcell. MinION data collection was initiated immediately, anddata were collected and analysed according to standard customerprotocols.

Results

FIG. 42 shows data collected over a 6-hour sequencing run using theabove protocol using an Oxford Nanopore Technologies MinION flowcellrunning the standard baseline sequencing script with MinKNOW 1.7.14software. The single crRNA probe used in this pulldown, AR400, isexpected to direct dCas9 to each of the seven 16S ribosomal gene siteslisted in FIG. 42D, with one position, identified as position vii,bearing a single mismatch at position −2 relative to the PAM site, andanother, identified as peak i, bearing a single mismatch at position −6relative to the PAM site. Of the ˜4.6 Mb genome, ˜35 kb (˜0.76%) of theinput DNA (7×the median read length, 5.9 kb) could be considered target.92,942 sequencing reads were obtained from this run and placed through astandard basecalling and alignment analysis workflow. 85,126 reads couldbe mapped to the E. coli MG1655 genome (NC_000913.3), of which 62,943(73.9%) mapped to within 3 median read lengths of each expected probehybridisation position. Pileup of the sequencing reads yielded acoverage depth of 9,000-10,000× for each of positions i, ii, iii, iv, vand vi.

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_0009133 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR364 /5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/Tether oligo /5cholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTCAR400 ‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/A1tR1/agaccaaagagggggacctt/AltR2/ProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-Terminal Twin-Strep-Tag withTEV-Cleavable Linker; Bold, Bracketed Shows the Portion Cleaved by TEV:

MDKKYSIGLAIGTNSVGWAVITDEYKVPSKKFKVLGNTDRHSIKKNLIGALLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENPINASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLTPNFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLRKQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNFDKNLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKTNRKVTVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKIIKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHPVENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVDAIVPQSFLKDDSIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKFDNLTKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLIREVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAVVGTALIKKYPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEVQTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVEKGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPEDNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDKPIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQSITGLYETRIDLSQLGGDGGSENLYFQ[GSGGSAWSHPQFEKGGGSGG GSGGGSAWSHPQFEK]

Example 7

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing, followingthe enrichment of the target molecule. In this Example, the target DNAmolecule is identified primarily by its sequence. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the dCas9 molecule. The dCas9 binds preferably to the targetmolecule by means of a crRNA directed against the ribosomal 16S (rrs)genes of Escherichia coli. ‘Off-target’ effects are minimized byapplying a thermal and salt stress to the dCas9 protein, followed by thepurification and elution of dCas9-target complexes on a capture surfacespecific to the tracrRNA, and the transfer of the dCas9-target complexesto a second specific capture surface specific to the crRNA. The releaseof the target from the first ‘purification’ bead is effected by thephenomenon known as toehold displacement. The target DNA molecule isadapted for nanopore sequencing, and the dCas9 remains bound to itstarget until displaced by the enzyme loaded on the adapter.

The crRNA also bears a 3′ DNA extension used for capture of the targetmolecule on a bead, column or surface (sequence d of FIG. 44). The dCas9also carries a tracrRNA molecule bearing a 5′ DNA extension (sequencea·c of FIG. 44) that enables capture of the target molecule on a‘purification’ bead, column or surface. The target is first separatedfrom non-target DNA by capture on beads bearing an oligonucleotidecomplementary to the DNA extension of the tracrRNA. Non-target DNA iswashed away during this step. The target molecule is eluted from thebead by toehold displacement, via the addition of an oligonucleotidethat competes for the binding to the bead with the DNA-extended tracrRNAmolecule. Following elution of the target molecule, the target is boundto a second ‘delivery’ bead via the DNA extension on the crRNA. Thetarget molecule is then adapted for nanopore sequencing by ligation toeither or both of its free, dA-tailed ends, while the dCas9-targetmolecule is still bound to the bead. The entire bead-target-RNP assemblyis then delivered to a flowcell for sequencing. The assembly is broughtto the wells of the flowcell by the application of a magnetic fieldplaced underneath the flowcell, or can be allowed to settle by gravity.Sequencing is initiated by flowing an oligonucleotide cholesteroltether, which hybridizes to the adaptor ends, over the beads, whichtethers the beads to the membrane. Alternatively, the cholesterol tethercan be introduced into the membrane during a ‘flush’ step, before thebead-target conjugate is added to the flowcell.

Methods

An E. coli whole-genome library, ONLA18816, was prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜7 kb using a Covaris gTube, following the manufacturer'sinstructions. This library was then end-repaired and dA-tailed using anNEB Ultra II kit, per the manufacturer's instructions. The end-repaired,dA-tailed, fragmented genomic DNA was subjected to 0.4×SPRI purificationand eluted from the SPRI beads in 0.1×TE.

200 nM DNA-extended tracrRNA (AR363) was added to a buffer containing 25mM HEPES-NaOH (pH 8.0), 150 mM NaCl and 1 mM MgCl₂ (known as dCas9binding buffer, BB). The tracrRNA was heated to 90° C. for 2 min andsnap-cooled on wet ice, after which 100 nM dCas9 (ONLP12326) was addedand the reaction incubated for 10 min at room temperature (˜21° C.). 250nM crRNA bearing a 3′ DNA extension (AR191) was then added to thereaction and incubated for a further 10 min at room temperature (˜21°C.). The final volume was 50 μL. This mixture was known asribonucleotide-protein complexes (RNPs).

To form dCas9-target complexes, 500 ng (˜1.2 μL) of the genomic DNA fromabove (ONLA18816) was added to the RNPs and incubated for 20 min at roomtemperature. The mixture was then incubated at 55° C. for 5 min toremove dCas9 not bound to its intended target. The mixture was subjectedto 1×SPRI purification as follows: 51 μL AMPure XP beads were added tothe mixture, mixed by gentle resuspension, and incubated for 10 min atroom temperature. The beads were pelleted using a magnetic separator,and washed twice with ˜250 μL of a buffer comprising 50 mM Tris-Cl (pH8.0 at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted by incubatingthe SPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0),40 mM KCl for 5 min. The beads were pelleted once more and thesupernatant, known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) wereincubated with 2.5 μL of AR667 capture oligo (comprising sequencesa′−b′, and a 3′ biotin moiety) in a buffer comprising 50 mM Tris-Cl (pH8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05% (v/v) Tween-20 for ˜1 h withagitation. Unbound oligonucleotide was removed by washing the beadstwice with the same buffer, pelleting the beads using a magneticseparator. This conjugate was known as ‘purification beads’.

Oligonucleotides AR132 and AR196 were hybridised using a PCRthermocycler by incubating 40 μM of each oligonucleotide in standard TEBuffer (10 mM Tris-Cl, 1 mM EDTA, pH 8.0)+200 mM NaCl, heating at 95° C.for 2 min, and cooling slowly to 25° C. over ˜2 h. 12.5 μL of thisduplex DNA, bearing an overhang complementary to the DNA extension ofthe crRNA sequence, were incubated with 50 μg Solulink ‘Nanolink’streptavidin magnetic beads (5 μL) in ˜120 μL of a buffer comprising 50mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05% (v/v) Tween-20for ˜1 h with agitation. Unbound oligonucleotide was removed by washingthe beads twice with the same buffer, pelleting the beads using amagnetic separator at each wash step. This conjugate was known as‘delivery beads’.

dCas9-bound target molecules were bound to purification beads byincubating 12.5 μL of SPRI eluate with 50 μg purification beads and 67.5μL Dynabeads kilobaseBINDER Binding Solution (Thermo Scientific Cat.#60101) for 20 min at room temperature with agitation. The beads werewashed three times with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4°C.), 150 mM NaCl, 1 mM EDTA, and once with a buffer containing 50 mMTris-Cl (pH 8.0 at 4° C.), 20 mM NaCl. Following this step, the beadswere pelleted and the supernatant removed. This sample was known as‘purification bead-target complex’.

Following immobilisation of the target DNA-RNP complex, target DNA waseluted from the purification bead by the addition of 20 μL of a buffercontaining 25 μM oligonucleotide AR668, bearing sequences a−b from FIG.44, 20 mM Tris-Cl (pH 8.0), and 100 mM NaCl, for 10 min at roomtemperature, with gentle agitation. The eluate was retained as‘purification bead eluate’.

The purification bead eluate was then immobilised on delivery beads byincubating the 20 μL of purification bead eluate with 1 μL of deliverybeads, and 105 μL Dynabeads kilobaseBINDER Binding Solution (ThermoScientific Cat. #60101) for 20 min with agitation. The beads weresubsequently washed three times with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 150 mM NaCl, 1 mM EDTA, and once with a buffercontaining 50 mM Tris-Cl (pH 8.0 at 4° C.), 20 mM NaCl. Following thisstep, the beads were pelleted and the supernatant removed. This samplewas known as ‘delivery bead-target complex’.

Enzyme-loaded adaptors (tube ‘AMX 1D’) from Oxford NanoporeTechnologies' 1D Sequencing Kit by Ligation (SQK-LSK108) were ligated tothe bead-target complex by resuspending the pelleted beads from abovewith a ligation mix comprising 12.5 μL 2×LAQA1 buffer (a gift from NewEngland Biolabs, Inc.), 7 μL nuclease-free water, 5 μL AMX 1D (part ofSQK-LSK108), and 0.5 μL T4 DNA Ligase (NEB Cat. #M0202). The beads wereincubated in the ligation mix with agitation for 10 min, pelleted, andwashed once with ˜125 μL of a buffer containing 50 mM Tris-Cl (pH 8.0 at4° C.), 150 mM NaCl, 1 mM EDTA. Following the wash, the beads werepelleted once more, and resuspended in 50 μL of RBF (a component ofSQK-LSK108), diluted to 1× according to the manufacturer's instructions.This mixture was known as the loading sample.

FIG. 44 shows the sequential series of steps described in this examplerequired to elute a target-bound dCas9 molecule from the purificationbead using a toehold displacement oligonucleotide, and transfer to asecond delivery bead for loading on an Oxford Nanopore MinION flow-cell.

An Oxford Nanopore MinION flowcell was primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The entire 50 μL of the loading samplewas pipetted dropwise into the SpotON port and the fluid allowed to wickinto the flowcell. MinION data collection was initiated immediately, anddata were collected and analysed according to standard customerprotocols.

Results

FIG. 45 shows the combinatorial effect of the heat stress, SPRIpurification, purification bead binding, toehold displacement, andcapture bead binding on the enrichment of E. coli 16S gene target fromnon-target E. coli DNA. The results are summarized in the Table below,which shows the % of reads on target.

Heat SPRI Toehold % on target A No No No 10.7% B No Yes No 29.5% C YesNo No 26.4% D Yes Yes No 48.4% E No No Yes 21.4% F No Yes Yes 30.0% GYes No Yes 50.2% H Yes Yes Yes 76.1%

Specifically, FIG. 45, H demonstrates the additive effect of all threeenrichment methods. The data of FIG. 45, H were collected over a 6-hoursequencing run using the above protocol using an Oxford NanoporeTechnologies MinION flowcell running the standard baseline sequencingscript with MinKNOW 1.7.14 software. The single crRNA probe used in thispulldown, AR191, is expected to direct dCas9 to each of the seven 16Sribosomal gene sites listed in FIG. 42D, with one position, identifiedas position vii, bearing a single mismatch at position −2 relative tothe PAM site, and another, identified as peak i, bearing a singlemismatch at position −6 relative to the PAM site. Of the ˜4.6 Mb genome,˜36 kb (˜0.78%) of the input DNA (7×the median read length, 5.1 kb)could be considered target.

10,482 sequencing reads were obtained from this run and placed through astandard basecalling and alignment analysis workflow. 9,245 reads couldbe mapped to the E. coli MG1655 genome (NC 000913.3), of which 7,975(76.1%) mapped to within 3 median read lengths of each expected probehybridisation position. Pileup of the sequencing reads yielded acoverage depth of >1,000× for each of positions i, ii, iii, iv, v andvi.

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR667 ATATTAGGGTCTTAAATAGCTCAGAAAAGAGTCATTGCA/iSp18//iSp18//iSp18//3BioTEG/ AR668 TGCAATGACTCTTTTCTGA/iBNA-meC//iBNA-G//iBNA-T//iBNA-A//iBNA-T//iBNA-T//iBNA-T/AAGACCCTAA/iBNA-T//iBNA-A/T AR132/5Phos/CGATCGTTCCGATCAGAACACAAAGATGTATTGCT AR196/5Phos/TGTTCTGATCGGAACGATCG/iSp18//iSp18//iSp18//3BioTEG/ Tether/5cholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTC oligo AR191/5Phos/rArGrArCrCrArArArGrArGrGrGrGrGrArCrCrUrUrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTGProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

Example 8

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing, followingthe enrichment of the target molecule. In this Example, the target DNAmolecule is identified primarily by its sequence. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the dCas9 molecule. The dCas9 binds preferably to the targetmolecule by means of a crRNA directed against the ribosomal 16S (rrs)genes of Escherichia coli. The binding of off-target, i.e., mismatched,regions, is reduced by substituting dCas9 with an otherwise wild-typebackground for a mutant derivative of the dCas9 enzyme, known as‘enhanced specificity dCas9’, and by applying a thermal and salt stressto the bound dCas9 protein, coupled with a SPRI purification step toremove excess, unbound dCas9 before subsequent purification on a capturebead surface. The target DNA molecule is adapted for nanoporesequencing, and the dCas9 remains bound to its target until displaced bythe enzyme loaded on the adapter.

The dCas9 carries a tracrRNA molecule bearing a 5′ DNA extension(sequence a of FIG. 41) that enables capture of the target molecule on abead-capture oligonucleotide conjugate that bears a DNA sequencecomplementary to this extension (sequence a′ of FIG. 41). In thisExample, the capture oligonucleotide is linked to the bead via a biotinmoiety. In this Example, the non-target DNA is washed away, and targetmolecules remain bound to the bead. The target molecule is then adaptedfor nanopore sequencing by ligation to either or both of its free,dA-tailed ends, while the dCas9-target molecule is bound to the bead.The entire bead-target-RNP assembly is then delivered to a flowcell forsequencing. The assembly is brought to the wells of the flowcell by theapplication of a magnetic field placed underneath the flowcell, or canbe allowed to settle by gravity. Sequencing is initiated by flowing anoligonucleotide cholesterol tether, which hybridizes to the adaptorends, over the beads, which tethers the beads to the membrane.Alternatively, the cholesterol tether can be introduced into themembrane during a ‘flush’ step, before the bead-target conjugate isadded to the flowcell.

Methods

An E. coli whole-genome library, ONLA18816, was prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜5.9 kb using a Covaris gTube, following the manufacturer'sinstructions. This library was then end-repaired and dA-tailed using anNEB Ultra II kit, per the manufacturer's instructions. Followingend-repair and dA-tailing, the fragmented genomic DNA was subjected to0.4×SPRI purification and eluted from the SPRI beads in 0.1×TE.

200 nM DNA-extended tracrRNA (AR363) was added to a buffer containing 25mM HEPES-NaOH (pH 8.0), 150 mM NaCl and 1 mM MgCl₂ (known as dCas9binding buffer). The tracrRNA was heated to 90° C. for 2 min andsnap-cooled on wet ice, after which 100 nM dCas9 with a wild-type(ONLP12326) or the ‘enhanced specificity’ dCas9 (ONLP12296) was addedand the reaction incubated for 10 min at room temperature (˜21° C.). 250nM crRNA bearing a 3′ extension (extension not used here; AR191) wasthen added to the reaction and incubated for a further 10 min at roomtemperature (˜21° C.). The final volume was 50 μL. This mixture wasknown as ribonucleotide-protein complexes (RNPs).

To form dCas9-target complexes, 500 ng (˜1.2 μL) of the genomic DNA fromabove (ONLA18816) was added to the RNPs and incubated for 20 min at roomtemperature. The mixture was then incubated at 55° C. for 5 min toremove dCas9 not bound to its intended target. The mixture was subjectedto 1×SPRI purification as follows: 51 μL AMPure XP beads were added tothe mixture, mixed by gentle resuspension, and incubated for 10 min atroom temperature. The beads were pelleted using a magnetic separator,and washed twice with ˜250 μL of a buffer comprising 50 mM Tris-Cl (pH8.0 at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted by incubatingthe SPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0),40 mM KCl for 5 min. The beads were pelleted once more and thesupernatant, known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) wereincubated with 2.5 of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide wasremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

dCas9-bound target molecules were bound to capture beads by incubating12.5 μL of SPRI eluate with 10 μg capture beads (1 μL) and 65 μLDynabeads kilobaseBINDER Binding Solution (Thermo Scientific Cat.#60101) for 20 min with agitation. The beads were subsequently washedthree times with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.),150 mM NaCl, 1 mM EDTA, and once with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 20 mM NaCl. Following this step, the beads werepelleted and the supernatant removed. This sample was known as‘bead-target complex’.

Enzyme-loaded adaptors (tube ‘AMX 1D’) from Oxford NanoporeTechnologies' 1D Sequencing Kit by Ligation (SQK-LSK108) were ligated tothe bead-target complex by resuspending the pelleted beads from abovewith a ligation mix comprising 12.5 μL 2×LAQA1 buffer (a gift from NewEngland Biolabs, Inc.), 7 μL nuclease-free water, 5 μL AMX 1D (part ofSQK-LSK108), and 0.5 μL T4 DNA Ligase (NEB Cat. #M0202). The beads wereincubated in the ligation mix with agitation for 10 min, pelleted, andwashed once with ˜125 μL of a buffer containing 50 mM Tris-Cl (pH 8.0 at4° C.), 150 mM NaCl, 1 mM EDTA to remove free, unligated adapter.Following the wash, the beads were pelleted once more, and resuspendedin 50 μL of RBF (a component of SQK-LSK108), diluted to 1×according tothe manufacturer's instructions. This mixture was known as the loadingsample.

FIG. 41 shows the expected appearance of thedCas9-crRNA-tracrRNA-target-bead conjugate, also known here as theloading sample.

An Oxford Nanopore MinION flowcell was primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The entire 50 μL of the loading samplewas pipetted dropwise into the SpotON port and the fluid allowed to wickinto the flowcell. MinION data collection was initiated immediately, anddata were collected and analysed according to standard customerprotocols.

Results

FIG. 46 shows data collected over a 6-hour sequencing run using theabove protocol using an Oxford Nanopore Technologies MinION flowcellrunning the standard baseline sequencing script with MinKNOW 1.7.14software. The single crRNA probe used in this pulldown, AR191, isexpected to direct dCas9 to each of the seven 16S ribosomal gene siteslisted in FIG. 42, D, with one position, identified with letters C andD, bearing a single mismatch at position ˜2 relative to the PAM site.This position corresponds to peak vii as identified in FIG. 42, D. Theratio of the height of the largest peak to the mismatch peak identifiedas C or D was 3.33:1 and 9.45:1 for the wild-type dCas9 and ‘enhancedspecificity’ dCas9 variants, respectively.

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR364 /5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/Tether oligo /5cholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTCAR191 /5Phos/rArGrArCrCrArArArGrArGrGrGrGrGrArCrCrUrUrGrUrUrUrUrArGrArGrCrUrArUrGrCrU AGCAATACATCTTTGProteinsONLP12296: S. pyogenes Cas9 D10A/H840A/K848A/K1003A/R1060A, known as‘enhanced specificity dCas9’: C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).ONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

Example 9

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing, followingthe enrichment of the target molecule. In this Example, the target DNAmolecule is identified primarily by its sequence, and the effects ofcatalytically active (‘live’, wild-type) and dead (D10A/H840A) Cas9 onread directionality bias were investigated. The directionality bias maybe used to enrich for a specific read direction. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the Cas9 molecule. Cas9 binds preferably to the targetmolecule by means of a crRNA directed against the ribosomal 16S (rrs)genes of Escherichia coli. ‘Off-target’ effects are reduced by applyinga thermal and salt stress to the bound Cas9 protein, coupled with a SPRIpurification step to remove excess, unbound Cas9 before subsequentpurification on a capture bead surface. The target DNA molecule isadapted for nanopore sequencing, and the Cas9 remains bound to itstarget until displaced by the enzyme loaded on the adapter.

The Cas9 carries a tracrRNA molecule bearing a 5′ DNA extension(sequence a of FIG. 41) that enables capture of the target molecule on abead-capture oligonucleotide conjugate that bears a DNA sequencecomplementary to this extension (sequence a′ of FIG. 41). In thisExample, the capture oligonucleotide is linked to the bead via a biotinmoiety. In this Example, the non-target DNA is washed away, and targetmolecules remain bound to the bead. The target molecule is then adaptedfor nanopore sequencing by ligation to either or both of its free,dA-tailed ends, while the Cas9-target molecule is bound to the bead. Theentire bead-target-RNP assembly is then delivered to a flowcell forsequencing. The assembly is brought to the wells of the flowcell by theapplication of a magnetic field placed underneath the flowcell, or canbe allowed to settle by gravity. Sequencing is initiated by flowing anoligonucleotide cholesterol tether, which hybridizes to the adaptorends, over the beads, which tethers the beads to the membrane.Alternatively, the cholesterol tether can be introduced into themembrane during a ‘flush’ step, before the bead-target conjugate isadded to the flowcell.

Catalytically active Cas9 would be expected to make a double-strandbreak at each of the target sites. If live Cas9 were to remain bound toonly one side of the cut, as demonstrated by Sternberg et al., Nature507, 62-67 (2014), then a significant directionality bias would beexpected.

Methods

An E. coli whole-genome library, ONLA18816, was prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜5.9 kb using a Covaris gTube, following the manufacturer'sinstructions. This library was then end-repaired and dA-tailed using anNEB Ultra II kit, per the manufacturer's instructions. Followingend-repair and dA-tailing, the fragmented genomic DNA was subjected to0.4×SPRI purification and eluted from the SPRI beads in 0.1×TE.

To form ribonucleotide-protein complexes with dead Cas9, 200 nMDNA-extended tracrRNA (AR363) was added to a buffer containing 25 mMHEPES-NaOH (pH 8.0), 150 mM NaCl and 1 mM MgCl₂ (known as dCas9 bindingbuffer). The tracrRNA was heated to 90° C. for 2 min and snap-cooled onwet ice, after which 100 nM dCas9 (ONLP12326) was added and the reactionincubated for 10 min at room temperature (˜21° C.). 250 nM crRNA (AR400)was then added to the reaction and incubated for a further 10 min atroom temperature (˜21° C.). The final volume was 50 μL. This mixture wasknown as dead RNPs.

To form ribonucleotide-protein complexes with live Cas9, 200 nMDNA-extended tracrRNA (AR363) was added to a buffer containing 20 mMHEPES, 100 mM NaCl, 5 mM MgCl₂, 0.1 mM EDTA, pH 6.5 @ 25° C., known asCas9 cleavage buffer. The tracrRNA was heated to 90° C. for 2 min andsnap-cooled on wet ice, after which 100 nM wild-type S. pyogenes Cas9(New England Biolabs, Inc., Cat #M0386T) was added and the reactionincubated for 10 min at room temperature (˜21° C.). 250 nM crRNA (AR400)was then added to the reaction and incubated for a further 10 min atroom temperature (˜21° C.). The final volume was 50 μL. This mixture wasknown as live RNPs.

To form Cas9-target complexes, 500 ng (˜1.2 μL) of the genomic DNA fromabove (ONLA18816) was added to the RNPs and incubated for 30 min at 30°C. (for dead RNPs) or for 30 min at 37° C. (for live RNPs). The mixturewas then incubated at 55° C. for 5 min to remove Cas9 not bound to itsintended target. The mixture was subjected to 1×SPRI purification asfollows: 51 μL AMPure XP beads were added to the mixture, mixed bygentle resuspension, and incubated for 10 min at room temperature. Thebeads were pelleted using a magnetic separator, and washed twice with˜250 μL of a buffer comprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2.5 MNaCl, 20% (w/v) PEG-8000, and eluted by incubating the SPRI beads with12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0), 40 mM KCl for 5min. The beads were pelleted once more and the supernatant, known as‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) wereincubated with 2.5 μL of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide wasremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

Cas9-bound target molecules were bound to capture beads by incubating12.5 μL of SPRI eluate with 10 μg capture beads (1 μL) and 65 μLDynabeads kilobaseBINDER Binding Solution (Thermo Scientific Cat.#60101) for 20 min with agitation. The beads were subsequently washedthree times with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.),150 mM NaCl, 1 mM EDTA, and once with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 20 mM NaCl. Following this step, the beads werepelleted and the supernatant removed. This sample was known as‘bead-target complex’.

Enzyme-loaded adaptors (tube ‘AMX 1D’) from Oxford NanoporeTechnologies' 1D Sequencing Kit by Ligation (SQK-LSK108) were ligated tothe bead-target complex by resuspending the pelleted beads from abovewith a ligation mix comprising 12.5 μL 2×LAQA1 buffer (a gift from NewEngland Biolabs, Inc.), 7 μL nuclease-free water, 5 μL AMX 1D (part ofSQK-LSK108), and 0.5 μL T4 DNA Ligase (NEB Cat. #M0202). The beads wereincubated in the ligation mix with agitation for 10 min, pelleted, andwashed once with ˜125 μL of a buffer containing 50 mM Tris-Cl (pH 8.0 at4° C.), 150 mM NaCl, 1 mM EDTA to remove free, unligated adapter.Following the wash, the beads were pelleted once more, and resuspendedin 50 μL of RBF (a component of SQK-LSK108), diluted to 1× according tothe manufacturer's instructions. This mixture was known as the loadingsample.

FIG. 41 shows the expected appearance of theCas9-crRNA-tracrRNA-target-bead conjugate, also known here as theloading sample.

An Oxford Nanopore MinION flowcell was primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The entire 50 μL of the loading samplewas pipetted dropwise into the SpotON port and the fluid allowed to wickinto the flowcell. MinION data collection was initiated immediately, anddata were collected and analysed according to standard customerprotocols.

Results

FIG. 47 shows data collected over a 6-hour sequencing run using theabove protocol using an Oxford Nanopore Technologies MinION flowcellrunning the standard baseline sequencing script with MinKNOW 1.7.14software, with either catalytically-dead Cas9 (‘dead’, A) or live Cas9(‘live’, B) used in the pulldown. The single crRNA probe used in thispulldown, AR400, is expected to direct Cas9 to each of the seven 16Sribosomal gene sites listed in FIG. 42, D. An additional peak, *, isalso seen, attributable to the elevated incubation temperature in thisexample. Coverage directionality plots for the ‘dead’ and ‘live’ Cas9,identified as C and D respectively, demonstrate the slight additionaldirectionality bias imposed by live Cas9.

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR364 /5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/Tether oligo /5cholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTCAR400 ‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/AltR1/agaccaaagagggggacctt/AltR2/ProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

Example 10

This Example describes a method for multiplexing the detection of amixture of specific polynucleotides in a complex background by nanoporesequencing, following the enrichment of the target molecules. In thisexample, the same E. coli total genomic sample was subjected tomultiple, separate enrichment dCas9 ‘pulldowns’ involving differentcombinations of crRNA probes. Each sample was ligated with a specificDNA barcode adapter sequence, enabling all samples to be sequencedsimultaneously using the same flowcell, and identified using theirbarcode adapter.

Methods

An E. coli whole-genome library, ONLA18816, was prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜5.9 kb using a Covaris gTube, following the manufacturer'sinstructions. This library was then end-repaired and dA-tailed using anNEB Ultra II kit, per the manufacturer's instructions. Followingend-repair and dA-tailing, the fragmented genomic DNA was subjected to0.4×SPRI purification and eluted from the SPRI beads in 0.1×TE. 500 ngof this library was then ligated to each of seven native barcode (NB)adapters, NB01, NB02, NB03, NB04, NB05, NB06 and NB07, from OxfordNanopore Technologies' Native Barcoding Kit 1D (Cat #EXP-NBD103),according to the manufacturer's instructions.

Seven samples were prepared individually, each with a differentcombination of crRNA probes, as follows: 220 nM DNA-extended tracrRNA(AR363) was added to a buffer containing 50 mM Tris-Cl (pH 8.0), 150 mMNaCl and 1 mM EDTA (known as dCas9-EDTA buffer). 100 nM dCas9(ONLP12326) was added and the reaction incubated for 10 min at roomtemperature (˜21° C.). 200 nM crRNA (total) was then added to thereaction and incubated for a further 10 min at room temperature (˜21°C.). The final volume was 50 μL. The combinations of crRNAs were asfollows: (NB01) AR398, (NB02) AR399, (NB03) AR400, (NB04) AR398 andAR399, (NB05) AR398 and AR400, (NB06) AR399 and AR400, (NB07) AR398,AR399 and AR400. These seven mixtures were known asribonucleotide-protein complexes (RNPs).

Each of the three crRNA probes used in this example target uniqueregions of the E. coli chromosome, according to the table below:

Target gene locations in crRNA probe Target gene name E. coli chromosome(bp) AR398 ftsK  937,211 AR399 csgG 1,099,778 AR400 Seven 16S ribosomalgenes 224,037; 2,700,448; (rrs) 3,380,179; 3,893,622; 3,987,345;4,118,473; 4,159,961.

To form RNP-target complexes, 500 ng of the genomic DNA carrying eachbarcode from above (ONLA18816) was added, separately, to each mixture ofRNPs (NB01 to NB07; seven in total) and incubated for 20 min at roomtemperature. Each mixture was then incubated at 55° C. for 5 min toremove dCas9 not bound to its intended target. The mixtures weresubjected to 1×SPRI purification as follows: ˜50 μL AMPure XP beads wereadded to the mixture, mixed by gentle resuspension, and incubated for 10min at room temperature. At this point, all seven samples were combinedinto a single tube. The beads were pelleted using a magnetic separator,and washed twice with ˜1 mL of a buffer comprising 50 mM Tris-Cl (pH 8.0at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted by incubating theSPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0), 40mM KCl for 5 min. The beads were pelleted once more and the supernatant,known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) wereincubated with 2.5 of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide wasremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

dCas9-bound target molecules were bound to capture beads by incubating12.5 μL of SPRI eluate with 30 μg capture beads (1 μL) and 65 μL of abuffer comprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA,0.05% (v/v) Tween-20 for 20 min with agitation. The beads weresubsequently washed three times with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 150 mM NaCl, 1 mM EDTA. Following this step, thebeads were pelleted and the supernatant removed. This sample was knownas ‘barcoded bead-target complexes’.

Enzyme-loaded adapter mix (tube ‘BAM’) from Oxford NanoporeTechnologies' Native Barcoding Kit 1D (EXP-NBD103) was ligated to thebarcoded bead-target complexes by resuspending the pelleted beads fromabove with a ligation mix comprising 12.5 μL 2×Blunt/TA Ligase MasterMix (New England Biolabs, Inc., Cat #M0367), 5 μL BAM (Oxford NanoporeTechnologies, Ltd., kit EXP-NBD103), and 7.5 μL nuclease-free water for10 min at room temperature, pelleted, and washed once with ˜125 μL of abuffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.), 150 mM NaCl, 1 mMEDTA to remove free, unligated adapter. Following the wash, the beadswere pelleted once more, and resuspended in 50 μL of RBF (a component ofSQK-LSK108), diluted to 1× according to the manufacturer's instructions.This mixture was known as the barcoded loading sample.

FIG. 48, A shows the expected appearance of thedCas9-crRNA-tracrRNA-target-bead conjugate, with ligated barcodeadapter, also known here as the barcoded loading sample. The sample issimilar to that shown in FIG. 41, except for the presence of a barcodeadapter sequence between target and enzyme-loaded adapter, which(besides the target sequence) identifies the sample.

An Oxford Nanopore MinION flowcell was primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The entire 50 μL of the barcoded loadingsample was pipetted dropwise into the SpotON port and the fluid allowedto wick into the flowcell. MinION data collection was initiatedimmediately, and data were collected and analysed according to standardcustomer workflows for Oxford Nanopore Technologies' Native BarcodingKits.

Results

FIG. 48, D shows coverage plots from reads aligned to the E. coligenome, collected over a 6-hour sequencing run using the abovemultiplexing protocol. The sample was run on a single Oxford NanoporeTechnologies MinION flowcell running the standard baseline sequencingscript with MinKNOW 1.7.14 software and analysed using Oxford NanoporeTechnologies workflows appropriate for the Native Barcoding Kit used.

Each barcode, NB01-NB07, is associated with the pulldown of a specificregion of the E. coli sequence according to the table below. Thecoverage plots of FIG. 48, D show the successful deconvolution of thebarcode sequence for each specific target region.

Barcode Probe(s) Intended targets NB01 AR398 ftsK NB02 AR399 csgG NB03AR400 rrs genes NB04 AR398 ftsK, csgG AR399 NB05 AR398 ftsK, rrs genesAR400 NB06 AR399 csgG, rrsB AR400 NB07 AR398 ftsK, csgG, rrs genes AR399AR400MaterialsDNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR364 /5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/Tether oligo /5CholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTCAR398 ‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/AltR1/tagatgatcaacgtaagtag/AltR2/ AR399‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/AltR1/ggatgggtggctgtttccct/AltR2/ AR400‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/AltR1/agaccaaagagggggacctt/AltR2/ProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

Example 11

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing, followingthe enrichment of the target molecule. In this Example, the target DNAmolecule is identified primarily by its sequence. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the dCas9 molecule. The dCas9 binds preferably to the targetmolecule by means of a crRNA directed against the ribosomal 16S (rrs)genes of Escherichia coli. ‘Off-target’ effects are reduced by applyinga thermal and salt stress to the bound dCas9 protein, coupled with aSPRI purification step to remove excess, unbound dCas9 before subsequentcapture on a bead surface.

In this Example, the DNA analyte may be adapted in different ways whilebound to the capture beads: either (1) high-molecular weight genomic DNAmay be sheared, end-repaired, dA-tailed, and ligated to an adapter usingappropriate ends; or (2) high-molecular weight DNA may be concomitantlysheared and adapted using a transposase system such as that employed bythe Oxford Nanopore Technologies Rapid 1D Sequencing Kit (SQK-RAD003).The adapter may permit other chemistries to be performed on the capturedanalyte while on the bead, while excess components such as free adaptersare washed away. As examples, the analyte may be adapted for OxfordNanopore Technologies' 1D² technology by ligating an appropriate adapterchemistry before ligating the enzyme adapter. Alternatively, adaptersmay be ligated that permit the amplification of the captured target byPCR, and release of the captured analyte from the bead.

Except for the example in which the captured target is released by PCR,the entire bead-target-RNP assembly is delivered to a flowcell forsequencing. The assembly is brought to the wells of the flowcell by theapplication of a magnetic field placed underneath the flowcell, or canbe allowed to settle by gravity. Sequencing is initiated by flowing anoligonucleotide cholesterol tether, which hybridizes to the adaptorends, over the beads, which tethers the beads to the membrane.Alternatively, the cholesterol tether can be introduced into themembrane during a ‘flush’ step, before the bead-target conjugate isadded to the flowcell.

Methods

An E. coli whole-genome library, ONLA18816, is prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜5.9 kb using a Covaris gTube, following the manufacturer'sinstructions. This library is end-repaired and dA-tailed using an NEBUltra II kit, per the manufacturer's instructions. Following end-repairand dA-tailing, the fragmented genomic DNA is subjected to 0.4×SPRIpurification and eluted from the SPRI beads in 0.1×TE. This sample isknown as ‘dA-tailed genomic DNA’.

500 ng of the dA-tailed genomic DNA is ligated to enzyme-loaded adaptors(‘AMX 1D’) from Oxford Nanopore Technologies' 1D Sequencing Kit byLigation (SQK-LSK108) in a comprising 12.5 μL 2×Blunt/TA Master Mix (NewEngland Biolabs, Inc., Cat #M0367), 7.5 nuclease-free water and 5 μL AMX1D (part of SQK-LSK108) for 10 min at room temperature. Following theligation, unligated adapter is purified away by 0.4×SPRI purificationand adapted library eluted from the SPRI beads in 10 mM Tris-Cl, 20 mMNaCl, pH 8.0. This sample is known as ‘pre-ligated genomic DNA’.

1 μg of an E. coli high-molecular weight genomic DNA sample is shearedand sticky-ends introduced in a single step by incubation of ˜1 μg DNAwith 2.5 μL FRA (from the SQK-RAD003 of Oxford Nanopore Technologies,Ltd.) in a total volume of 10 μL at 30° C. for 20 min, followed by 80°C. for 1 min. 500 μL AMPure XP SPRI beads are washed five times innuclease-free water, followed by resuspension in the original volume ofa buffer comprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2.5 M NaCl, 20%(w/v) PEG-8000, yielding ‘washed SPRI beads’. The genomic DNA sample issubjected to purification using 0.4× ‘washed SPRI beads’, and eluted byincubating the SPRI beads with 12.5 μL of a buffer comprising 0.1×TE atroom temperature for 5 min. The beads are pelleted once more and thesupernatant, known as ‘transposase-fragmented genomic DNA’, retained.

200 nM DNA-extended tracrRNA (AR363) is added to a buffer containing 25mM HEPES-NaOH (pH 8.0), 150 mM NaCl and 1 mM MgCl₂ (known as dCas9binding buffer). The tracrRNA is heated to 90° C. for 2 min andsnap-cooled on wet ice, after which 100 nM dCas9 (ONLP12326) was addedand the reaction incubated for 10 min at room temperature (˜21° C.). 250nM crRNA (AR400) is then added to the reaction and incubated for afurther 10 min at room temperature (˜21° C.). The final volume was 50 μLper reaction. This mixture is known as ribonucleotide-protein complexes(RNPs).

To form dCas9-target complexes, 500 ng (˜1.2 μL) of either thetransposase-fragmented genomic DNA, dA-tailed genomic DNA or pre-ligatedgenomic DNA is added to the RNPs per reaction and incubated for 20 minat room temperature. The mixture is then incubated at 55° C. for 5 minto remove dCas9 not bound to its intended target. Each mixture issubjected to 1×SPRI purification as follows: 51 μL AMPure XP beads areadded to the mixture, mixed by gentle resuspension, and incubated for 10min at room temperature. The beads are pelleted using a magneticseparator, washed twice with ˜250 μL of a buffer comprising 50 mMTris-Cl (pH 8.0 at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted byincubating the SPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS(pH 10.0), 40 mM KCl for 5 min. The beads were pelleted once more andthe supernatant, known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) areincubated with 2.5 μL of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide wasremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

dCas9-bound target molecules (bound to transposase-fragmented genomicDNA, dA-tailed genomic DNA or pre-adapted genomic DNA) are bound tocapture beads by incubating 12.5 μL of SPRI eluate with 10 μg capturebeads (1 μL) and 65 μL Dynabeads kilobaseBINDER Binding Solution (ThermoScientific Cat. #60101) for 20 min with agitation. The beads are washedthree times with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.),150 mM NaCl, 1 mM EDTA, and once with a buffer containing 50 mM Tris-Cl(pH 8.0 at 4° C.), 20 mM NaCl. Following this step, the beads arepelleted and the supernatant removed. This sample is known as‘bead-target complex’.

In one reaction, enzyme-loaded adaptors (tube ‘AMX 1D’) from OxfordNanopore Technologies' 1D Sequencing Kit by Ligation (SQK-LSK108) areligated to dA-tailed genomic DNA captured on beads by resuspending thepelleted beads from above with a ligation mix comprising 12.5 μL2×Blunt/TA Master Mix (New England Biolabs, Inc., Cat #M0367), 7.5nuclease-free water and 5 μL AMX 1D (part of SQK-LSK108) for 10 min atroom temperature. This sample is known as the ‘bead-ligated 1D’ sample.

In a second reaction, the analyte is prepared for ‘1D²’ sequencing byperforming two sequential ligations while the target is bound to thebeads. In the first ligation reaction, the beads are resuspended in 2.5μl 1D² Adapter, 25 μl Blunt/TA Ligase Master Mix, and 22.5 nuclease-freewater and incubated for 10 min at room temperature. After 10 minincubation, a further 10 μL BAM and 10 μL Blunt/TA Ligase Master Mix areadded to the beads and incubated for a further 10 min at roomtemperature. This sample is known as the ‘1D²’ sample.

In a third reaction, the transposase-fragmented genomic DNA bound tobeads is adapted for sequencing by resuspending the beads in a buffercontaining 1×RBF, and 1 μL RPD (from SQK-RAD003) for 10 min. This sampleis known as the ‘Rapid 1D’ sample.

Following each of the above ligations, the beads are pelleted after theligation, washed once in 125 μL of a buffer containing 50 mM Tris-Cl (pH8.0 at 4° C.), 150 mM NaCl, 1 mM EDTA, and resuspended in 50 μL of RBF(from SQK-LSK108), diluted to 1× according to the manufacturer'sinstructions. This mixture is known as the loading sample.

For the sample containing pre-adapted genomic DNA bound to beads, thebeads are washed once more in 125 μL of a buffer containing 50 mMTris-Cl (pH 8.0 at 4° C.), 150 mM NaCl, 1 mM EDTA, and resuspended in 50μL of RBF (a component of SQK-LSK108), diluted to 1× according to themanufacturer's instructions. This mixture is known as the ‘pre-ligatedsample’.

In a further reaction, PCR-adaptors (tube ‘PCA’) from Oxford NanoporeTechnologies' Low-Input By PCR kit (SQK-LWP001) are ligated to dA-tailedgenomic DNA captured on beads by resuspending the pelleted beads fromabove with a ligation mix comprising 50 μL 2× Blunt/TA Master Mix (NewEngland Biolabs, Inc., Cat #M0367), 30 μL nuclease-free water and 20 μLPCA for 10 min at room temperature. Following the ligation, the beadsare washed in a further 125 μL of 10 mM Tris-Cl (pH 8.0), 20 mM NaCl,and resuspended in a mixture containing 50 μL LongAmp Taq 2× Master Mix(NEB Cat #M0287), 2 μL WGP primers, and 48 μL nuclease-free water. Themixture is subjected to PCR amplification, including 30 sec denaturationat 94° C., and 10 cycles of 30 sec denaturation at 94° C., 30 secannealing at 62° C., and 500 sec extension at 65° C. This sample issubjected to 0.4×SPRI purification using AMPure XP beads pre-washed asdescribed above. The sample is eluted from SPRI beads in 10 μL of 10 mMTris-Cl (pH 8.0), 20 mM NaCl, for 5 min at room temperature. Followingelution from the SPRI beads, 1 μL of RPD (SQK-LWP001) are added and themixture incubated for 10 min at room temperature to ligate sequencingadapters by click chemistry. A further 35 μL of RBF, 25 of LLB and 5 μLnuclease-free water are also added. This sample is known as the TUCsample.

Five Oxford Nanopore MinION flowcells are primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. Each sample: 1D², PCR, Rapid 1D,bead-ligated, and pre-ligated, is pipetted dropwise into the SpotON portof each of the five flowcells and the fluid allowed to wick into theflowcell. MinION data collection is initiated immediately, and data arecollected and analysed according to standard customer protocols.

FIG. 49 shows three example workflows for (1) the enzyme-free detectionof dCas9, via the ligation of an enzyme-free adapter to the ends of acaptured target analyte bound to beads; (2) the enrichment of target bythe ligation of PCR adapters, followed by PCR amplification of thetarget, as described above, to release target from beads; and (3) thesequential ligation of 1D² barcode adapters, followed by sequencingadapters, for high-accuracy nanopore sequencing.

FIG. 50 shows an example workflow, described in Example 11, for therapid enrichment of target from high-molecular weight DNA, bytransposase-mediated shearing of the DNA, while concomitantly adding asticky end for adapter ligation. dCas9 is then bound to the sheared DNA,as described in Example 11; off-target effects are minimised by a stressstep, and sequencing adapters ligated via click chemistry. This workflowmakes use of the Oxford Nanopore Technologies SQK-RAD003 kit, with theinsertion of a Cas9 binding and bead capture step between thetransposase fragmentation and adapter attachment steps, as described inExample 10.

Results

The results from each of the workflows described above yield resultsvery similar to those depicted in FIG. 42, i.e., targeted enrichment ofthe E. coli rrs genes from a whole-genome sample. The only differencesin this example are the methods of end-preparation for attachingsequencing adapters. The ability to attach 1D² adapters, via sequentialligation of a barcode followed by an enzyme-loaded sequencing adapter,increases the single-molecule accuracy of nanopore sequencing. Theability to attach adapters via a transposase, followed by enzyme-freeligation via click chemistry, may afford the end-user greaterconvenience, enabling a faster sample preparation time. The ability toattach PCR adapters may afford the end-user considerably improvedsensitivity, enabling the detection of the enriched target from muchlower input amounts of starting material.

The ligation of sequencing adapters while the target analyte is bound tobeads enables excess adapters, which may poison the nanopore sequencingreaction by fouling the pore, or depleting nucleotide concentration, tobe conveniently washed away after the ligation step

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR363TACATTTAAGACCCTAATAT/iSp18/mA*mG*mCmAmUmAmGmCmArArGrUrUrArArArArUrArArGrGrCrUrArGrUrCrCrGrUrUrArUrCrArAmCmUmUmGmAmAmAmAmAmGmUmGmGmCmAmCmCmGmAmG mUmCmGmGmUmGmCmU*mU*mUAR364 /5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/Tether oligo /5CholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTCAR400 ‘Alt-R’ Cas9 crRNA from Integrated DNA Technologies, Inc:/AltR1/agaccaaagagggggacctt/AltR2/ProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

Example 12

This Example describes a method for the detection of a specificpolynucleotide in a complex background by nanopore sequencing, followingthe enrichment of the target molecule. In this example, the target DNAmolecule is identified primarily by its sequence. The target molecule isseparated from the background by means of a ‘pulldown’ via a capturemoiety on the catalytically active (‘live’, wild-type) Cpf1 (ONLP12350)or dead (E993A or D908A) dCpf1 (ONLZ11882 or ONLZ11883). The Cpf1 ordCpf1 binds preferably to the target molecule by means of a crRNAdirected against the ribosomal 16S (rrs) genes of Escherichia coli.‘Off-target’ effects are reduced by applying a thermal and salt stressto the bound Cpf1 or dCpf1 protein, coupled with a SPRI purificationstep to remove excess, unbound Cpf1 or dCpf1 before subsequent captureon a bead surface.

The Cpf1 or dCpf1 carries a crRNA molecule bearing a 5′ DNA extension(AR766) that enables capture of the target molecule on a bead-captureoligonucleotide conjugate that bears a DNA sequence complementary tothis extension (AR364), as depicted in figure RB12. In this Example, thecapture oligonucleotide is linked to the bead via a biotin moiety. Inthis Example, the non-target DNA is washed away, and target moleculesremain bound to the bead. The target molecule is then adapted fornanopore sequencing by ligation to either or both of its free, dA-tailedends, while the Cpf1 target molecule is bound to the bead. The entirebead-target-RNP assembly is then delivered to a flowcell for sequencing.The assembly is brought to the wells of the flowcell by the applicationof a magnetic field placed underneath the flowcell, or can be allowed tosettle by gravity. Sequencing is initiated by flowing an oligonucleotidecholesterol tether, which hybridizes to the adaptor ends, over thebeads, which tethers the beads to the membrane. Alternatively, thecholesterol tether can be introduced into the membrane during a ‘flush’step, before the bead-target conjugate is added to the flowcell.

Methods

An E. coli whole-genome library, ONLA18816, is prepared by randomfragmentation of E. coli high-molecular weight genomic DNA to a mediansize of ˜5.9 kb using a Covaris gTube, following the manufacturer'sinstructions. This library is end-repaired and dA-tailed using an NEBUltra II kit, per the manufacturer's instructions. Following end-repairand dA-tailing, the fragmented genomic DNA is subjected to 0.4×SPRIpurification and eluted from the SPRI beads in 0.1×TE. This sample isknown as ‘dA-tailed genomic DNA’.

250 nM DNA-extended crRNA (AR766) is added to a buffer containing 50 mMTris-HCl (pH 8.0), 100 mM NaCl, 10 mM MgCl₂ and 1 mM DTT (known as Cpf1binding buffer). The crRNA is heated to 95° C. for 2 min and allowed tocool to room temperature, after which 500 nM Cpf1 (ONLP12326) is addedand the reaction incubated for 20 min at room temperature (˜21° C.).This mixture is known as ribonucleotide-protein complexes (RNPs).

To form Cpf1-target complexes, 500 ng (˜1.2 μL) of the genomic DNA fromabove (ONLA18816) is added to the RNPs and incubated for 60 min at roomtemperature. The mixture is incubated at 55° C. for 5 min to remove Cpf1not bound to its intended target. The mixture is subjected to 1×SPRIpurification as follows: 51 μL AMPure XP beads are added to the mixture,mixed by gentle resuspension, and incubated for 10 min at roomtemperature. The beads are pelleted using a magnetic separator, andwashed twice with ˜250 μL of a buffer comprising 50 mM Tris-Cl (pH 8.0at 4° C.), 2.5 M NaCl, 20% (w/v) PEG-8000, and eluted by incubating theSPRI beads with 12.5 μL of a buffer comprising 40 mM CAPS (pH 10.0), 40mM KCl for 5 min. The beads are pelleted once more and the supernatant,known as ‘SPRI eluate’, retained.

50 μg Solulink ‘Nanolink’ streptavidin magnetic beads (5 μL) areincubated with 2.5 μL of AR364 capture oligo in ˜120 μL of a buffercomprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2 M NaCl, 1 mM EDTA, 0.05%(v/v) Tween-20 for ˜1 h with agitation. Unbound oligonucleotide isremoved by washing the beads twice with the same buffer, pelleting thebeads using a magnetic separator. This conjugate was known as ‘capturebeads’.

Cpf1 or dCpf1-bound target molecules are bound to capture beads byincubating 12.5 of SPRI eluate with 10 μg capture beads (1 μL) and 65 μLDynabeads kilobaseBINDER Binding Solution (Thermo Scientific Cat.#60101) for 20 min with agitation. The beads are washed three times witha buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.), 150 mM NaCl, 1 mMEDTA, and once with a buffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.),20 mM NaCl. Following this step, the beads are pelleted and thesupernatant removed. This sample is known as ‘bead-target complex’.

Enzyme-loaded adaptors (tube ‘AMX 1D’) from Oxford NanoporeTechnologies' 1D Sequencing Kit by Ligation (SQK-LSK108) are ligated todA-tailed genomic DNA captured on beads by resuspending the pelletedbeads from above with a ligation mix comprising 12.5 μL 2×Blunt/TAMaster Mix (New England Biolabs, Inc., Cat #M0367), 7.5 μL nuclease-freewater and 5 μL AMX 1D (part of SQK-LSK108) for 10 min at roomtemperature. This sample is known as the ‘bead-ligated 1D’ sample.

The beads are pelleted after the ligation, washed once in 125 μL of abuffer containing 50 mM Tris-Cl (pH 8.0 at 4° C.), 150 mM NaCl, 1 mMEDTA, and resuspended in 50 μL of RBF (from SQK-LSK108), diluted to 1×according to the manufacturer's instructions. This mixture is known asthe loading sample.

An Oxford Nanopore MinION flowcell is primed with 800 μL 1×RBFcontaining 50 nM tether oligo pipetted via its inlet port, followed by apause of 10 min, then 200 μL of the same mixture pipetted via its inletport with the SpotON port open. The loading sample is pipetted dropwiseinto the SpotON port of the flowcell and the fluid allowed to wick intothe flowcell. MinION data collection is initiated immediately, and dataare collected and analysed according to standard customer protocols.

Results

The results from the workflow described above yields results verysimilar to those depicted in FIG. 42 and to those depicted in FIG. 47,i.e., targeted enrichment of the E. coli rrs genes from a whole-genomesample. The live Cpf1 could impose a directionality bias. Thedifferences in this Example are the CRISPR protein used to form the RNPs(i.e. Cpf1 or dCpf1, not Cas9 or dCas9), and the use of a singleDNA-extended crRNA to form the RNPs.

The ligation of sequencing adapters while the target analyte is bound tobeads enables excess adapters, which may poison the nanopore sequencingreaction by fouling the pore, or depleting nucleotide concentration, tobe conveniently washed away after the ligation step.

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) E. coliNCBI Reference Sequence: NC_000913.3 genomic DNA, str. K-12, substr.MG1655 as ONLA18816 AR766TACATTTAAGACCCTAATATttttttrUrArArUrUrUrCrUrArCrUrCrUrUrGrUrArGrArUrArUrCrArUrGrGrCrUrCrArGrArUrUrGrArArCrGrC AR364/5Phos/ATATTAGGGTCTTAAATGTA/iSp18//iSp18//iSp18//3BioTEG/ Tether/5cholTEG/TT/iSp18//iSp18//iSp18//iSp18/TTGACCGCTCGCCTC oligoProteinsONLP12350: Acidaminococcus sp. Cpf1, N-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV:

[MSAWSHPQFEKGGGSGGGSGGSAWSHPQFEKSGGGGGENLYFQ]GMTQFEGFTNLYQVSKTLRFELIPQGKTLKHIQEQGFIEEDKARNDHYKELKPIIDRIYKTYADQCLQLVQLDWENLSAAIDSYRKEKTEETRNALIEEQATYRNAIHDYFIGRTDNLTDAINKRHAEIYKGLFKAELENGKVLKQLGTVTTTEHENALLRSEDKFTTYFSGEYENRKNVFSAEDISTAIPHRIVQDNFPKEKENCHIFTRLITAVPSLREHFENVKKAIGIFVSTSIEEVFSFPFYNQLLTQTQIDLYNQLLGGISREAGTEKIKGLNEVLNLAIQKNDETAHIIASLPHRFIPLEKQILSDRNTLSFILEEFKSDEEVIQSFCKYKTLLRNENVLETAEALFNELNSIDLTHIFISHKKLETISSALCDHWDTLRNALYERRISELTGKITKSAKEKVQRSLKHEDINLQEIISAAGKELSEAFKQKTSEILSHAHAALDQPLPTTLKKQEEKEILKSQLDSLLGLYHLLDWFAVDESNEVDPEFSARLTGIKLEMEPSLSFYNKARNYATKKPYSVEKFKLNFQMPTLASGWDVNKEKNNGAILFVKNGLYYLGIMPKQKGRYKALSFEPTEKTSEGFDKMYYDYFPDAAKMIPKCSTQLKAVTAHFQTHTTPILLSNNFIEPLEITKEIYDLNNPEKEPKKFQTAYAKKTGDQKGYREALCKWIDFTRDELSKYTKTTSIDLSSLRPSSQYKDLGEYYAELNPLLYHISFQRIAEKEIMDAVETGKLYLFQIYNKDFAKGHHGKPNLHTLYWTGLFSPENLAKTSIKLNGQAELFYRPKSRMKRMAHRLGEKMLNKKLKDQKTPIPDTLYQELYDYVNHRLSHDLSDEARALLPNVITKEVSHEIIKDRRFTSDKEFFHVPITLNYQAANSPSKFNQRVNAYLKEHPETPIIGIDRGERNLIYITVIDSTGKILEQRSLNTIQQFDYQKKLDNREKERVAARQAWSVVGTIKDLKQGYLSQVIHEIVDLMIHYQAVVVLENLNEGFKSKRTGIAEKAVYQQFEKMLIDKLNCLVLKDYPAEKVGGVLNPYQLTDQFTSFAKMGTQSGELFYVPAPYTSKIDPLTGFVDPFVWKTIKNHESRKHFLEGFDFLHYDVKTGDFILHFKMNRNLSFQRGLPGEMPAWDIVFEKNETQFDAKGTPFIAGKRIVPVIENHRFTGRYRDLYPANELIALLEEKGIVFRDGSNILPKLLENDDSHAIDTMVALIRSVLQMRNSNAATGEDYINSPVRDLNGVCFDSRFQNPEWPMDADANGAYHIALKGQLLLNHLKESKDLKLQNGISNQDWLAYIQE LRNGSGLNDIFEAQKIEWHEONLZ11882: Acidaminococcus sp. Cpf1 D908A, N-terminal Twin-Strep-tagwith TEV-cleavable linker; bold, bracketed shows the portion cleaved byTEV:

[MSAWSHPQFEKGGGSGGGSGGSAWSHPQFEKSGGGGGENLYFQ]GMTQFEGFTNLYQVSKTLRFELIPQGKTLKHIQEQGFIEEDKARNDHYKELKPIIDRIYKTYADQCLQLVQLDWENLSAAIDSYRKEKTEETRNALIEEQATYRNAIHDYFIGRIDNLTDAINKRHAEIYKGLFKAELENGKVLKQLGTVITTEHENALLRSEDKFTTYFSGEYENRKNVESAEDISTAIPHRIVQDNFPKFKENCHIFTRLITAVPSLREHFENVKKAIGIFVSTSIEEVFSFPFYNQLLTQTQIDLYNQLLGGISREAGTEKIKGLNEVLNLAIQKNDETAHIIASLPHRFIPLEKQILSDRNTLSFILEEEKSDEEVIQSECKYKTLLRNENVLETAEALFNELNSIDLTHIFISHKKLETISSALCDHWDTLRNALYERRISELTGKITKSAKEKVQRSLKHEDINLQEIISAAGKELSEAFKQKTSEILSHAHAALDQPLPTTLKKQEEKEILKSQLDSLLGLYHLLDWFAVDESNEVDPEFSARLTGIKLEMEPSLSFYNKARNYATKKPYSVEKFKLNFQMPTLASGWDVNKEKNNGAILFVKNGLYYLGIMPKQKGRYKALSFEPTEKTSEGFDKMYYDYFPDAAKMIPKCSTQLKAVTAHFQTHTTPILLSNNFIEPLEITKEIYDLNNPEKEPKKFQTAYAKKTGDQKGYREALCKWIDETRDELSKYTKTTSIDLSSLRPSSQYKDLGEYYAELNPLLYHISFQRIAEKEIMDAVETGKLYLFQIYNKDFAKGHHGKPNLHTLYWTGLFSPENLAKTSIKLNGQAELFYRPKSRMKRMAHRLGEKMLNKKLKDQKTPIPDTLYQELYDYVNHRLSHDLSDEARALLPNVITKEVSHEIIKDRRFTSDKEFFHVPITLNYQAANSPSKFNQRVNAYLKEHPETPIIGIARGERNLIYITVIDSTGKILEQRSLNTIQQFDYQKKLDNREKERVAARQAWSVVGTIKDLKQGYLSQVIHEIVDLMIHYQAVVVLENLNEGEKSKRTGIAEKAVYQQFEKMLIDKLNCLVLKDYPAEKVGGVLNPYQLTDQFTSFAKMGTQSGELFYVPAPYTSKIDPLTGFVDPFVWKTIKNHESRKHFLEGFDFLHYDVKTGDFILHFKMNRNLSFQRGLPGEMPAWDIVFEKNETQFDAKGTPFIAGKRIVPVIENHRFTGRYRDLYPANELIALLEEKGIVERDGSNILPKLLENDDSHAIDTMVALIRSVLQMRNSNAATGEDYINSPVRDLNGVCEDSREQNPEWPMDADANGAYHIALKGQLLLNHLKESKDLKLQNGISNQDWLAYIQE LRNGSGLNDIFEAQKIEWHEONLZ11883: Acidaminococcus sp. Cpf1 E993A, N-terminal Twin-Strep-tagwith TEV-cleavable linker; bold, bracketed shows the portion cleaved byTEV:

[MSAWSHPQFEKGGGSGGGSGGSAWSHPQFEKSGGGGGENLYFQ]GMTQFEGFTNLYQVSKTLRFELIPQGKTLKHIQEQGFIEEDKARNDHYKELKPIIDRIYKTYADQCLQLVQLDWENLSAAIDSYRKEKTEETRNALIEEQATYRNAIHDYFIGRTDNLTDAINKRHAEIYKGLFKAELENGKVLKQLGTVTTTEHENALLRSEDKFTTYFSGEYENRKNVESAEDISTAIPHRIVQDNFPKEKENCHIFTRLITAVPSLREHFENVKKAIGIFVSTSIEEVFSFPFYNQLLTQTQIDLYNQLLGGISREAGTEKIKGLNEVLNLAIQKNDETAHIIASLPHRFIPLEKQILSDRNTLSFILEEEKSDEEVIQSECKYKTLLRNENVLETAEALFNELNSIDLTHIFISHKKLETISSALCDHWDTLRNALYERRISELTGKITKSAKEKVQRSLKHEDINLQEIISAAGKELSEAFKQKTSEILSHAHAALDQPLPTTLKKQEEKEILKSQLDSLLGLYHLLDWFAVDESNEVDPEFSARLTGIKLEMEPSLSFYNKARNYATKKPYSVEKFKLNFQMPTLASGWDVNKEKNNGAILFVKNGLYYLGIMPKQKGRYKALSFEPTEKTSEGFDKMYYDYFPDAAKMIPKCSTQLKAVTAHFQTHTTPILLSNNFIEPLEITKEIYDLNNPEKEPKKFQTAYAKKTGDQKGYREALCKWIDETRDELSKYTKTTSIDLSSLRPSSQYKDLGEYYAELNPLLYHISFQRIAEKEIMDAVETGKLYLFQIYNKDFAKGHHGKPNLHTLYWTGLFSPENLAKTSIKLNGQAELFYRPKSRMKRMAHRLGEKMLNKKLKDQKTPIPDTLYQELYDYVNHRLSHDLSDEARALLPNVITKEVSHEIIKDRRFTSDKEFFHVPITLNYQAANSPSKFNQRVNAYLKEHPETPIIGIDRGERNLIYITVIDSTGKILEQRSLNTIQQFDYQKKLDNREKERVAARQAWSVVGTIKDLKQGYLSQVIHEIVDLMIHYQAVVVLANLNFGGKSKRTGIAEKAVYQQFEKMLIDKLNCLVLKDYPAEKVGGVLNPYQLTDQFTSFAKMGTQSGFLFYVPAPYTSKIDPLTGFVDPFVWKTIKNHESRKHFLEGFDFLHYDVKTGDFILHFKMNRNLSFQRGLPGEMPAWDIVFEKNETQFDAKGTPFIAGKRIVPVIENHRFTGRYRDLYPANELIALLEEKGIVFRDGSNILPKLLENDDSHAIDTMVALIRSVLQMRNSNAATGEDYINSPVRDLNGVCFDSRFQNPEWPMDADANGAYHIALKGQLLLNHLKESKDLKLQNGISNQDWLAYIQE LRNGSGLNDIFEAQKIEWHE

Example 13

This Example describes a method for the rapid detection and quantitationof a specific bacteriophage lambda polynucleotide in a human backgroundby nanopore detection. In this Example, the target DNA is contacted byone or more dCas9-RNP complex(es) carrying an affinity tag that may beused for the immobilization of the target molecule on a surface(‘immobilisation dCas9 complex(es)’), while one or more additionaldCas9-RNP complexes (‘barcode Cas9 complex(es)’) contact the target DNAmolecule in a second region. The ‘barcode dCas9 complexes’ carry anenzyme-loaded adapter molecule whose current signature is used toconfirm that the dCas9 bound to its target. The presence of the targetregion is identified by the barcode, while the sensitivity of detectionof the target over non-target DNA is enhanced by immobilisation on themembrane surface. Thus, both types of dCas9 complex are required to bebound to the same target molecule for the successful detection of thebarcode sequence. In this example, the non-target DNA need not be washedaway.

Methods

A bacteriophage lambda whole-genome library (NEB Cat #N3013) is preparedby random fragmentation of E. coli high-molecular weight genomic DNA toa median size of ˜5 kb using a Covaris gTube, following themanufacturer's instructions. A human whole-genome library is alsoprepared by random fragmentation of high-molecular weight genomic DNA(Sigma Aldrich, Cat #000000011691112001) to a median size of ˜5 kb usinga Covaris gTube, following the manufacturer's instructions.

‘Enzyme-loaded crRNAs’ are prepared by hybridising oligonucleotidesOLIGO_1, a crRNA oligonucleotide bearing a 3′ DNA extension, andOLIGO_2, a DNA adapter oligonucleotide, in a PCR machine in 10 mMTris-Cl (pH 8.0), 1 mM EDTA, 200 mM NaCl at 40 μM of eacholigonucleotide by heating to 95° C. for 2 min and slow cooling to 20°C. over ˜2 h. This annealing reaction yields a hybrid molecule with acrRNA portion, and a DNA-extended portion that is duplex and bears a 3′dA-overhang, known as ‘crRNA adapter’. The AMX 1D enzyme adaptor fromOxford Nanopore Technologies' 1D Sequencing Kit By Ligation (SQK-LSK108)is ligated to ‘crRNA adapter’ by incubating 5 μL AMX 1D (which carries adT-overhang) with 1 μM of ‘crRNA adapter’ (1.25 μL), 50 μL 2×NEBBlunt/TA Master Mix and 43.8 μL nuclease-free water in a total volume of˜100 μL for 10 min at room temperature. The excess unligated material ispurified away by the addition 3.8× volumes of AMPure XP SPRI beads thathave been equilibrated in 50 mM Tris-Cl (pH 8.0 at 4° C.), 2.5 M NaCl,28% (w/v) PEG-8000, eluting the ‘enzyme-loaded crRNAs’ in a buffercomprising 10 mM Tris-Cl (pH 8.0), 20 mM NaCl.

‘Cholesterol tethers’ were prepared by hybridising oligonucleotidesAR131 and AR132 in a PCR machine in 10 mM Tris-Cl (pH 8.0), 1 mM EDTA,200 mM NaCl at 40 μM of each oligonucleotide by heating to 95° C. for 2min and slow cooling to 20° C. over ˜2 h. This annealing reaction yieldsa hybrid molecule with a 3′ overhang bearing complementarity to thecrRNA AR140 below.

200 nM ‘Alt-R’ tracrRNA (Integrated DNA Technologies, Inc., Cat#1072532), is added to a buffer containing 25 mM HEPES-NaOH (pH 8.0),150 mM NaCl and 1 mM MgCl₂ (known as dCas9 binding buffer). The tracrRNAis heated to 90° C. for 2 min and snap-cooled on wet ice, after which100 nM dCas9 (ONLP12326) is added and the reaction incubated for 10 minat room temperature (˜21° C.). An equimolar mix of two crRNAs is added:125 nM AR140, bearing one 3′ DNA extension sequence, and 125 nM‘enzyme-loaded crRNA’ from above, bearing the sequencing adapter. Theincubation is continued at room temperature (˜21° C.) for 10 min. Thefinal volume is ˜50 μL. This mixture is known as ribonucleotide-proteincomplexes (RNPs).

To form dCas9-target complexes, a varying amount of the bacteriophagelambda genomic DNA from above from 0 to 100 ng is mixed with a constant1 (in 5 μL total) of human DNA from above, added to the RNPs andincubated for 20 min at room temperature. The mixture is subjected to1×SPRI purification to remove excess unbound dCas9, crRNA and tracrRNAas follows: 51 μL AMPure XP beads are added to the mixture, mixed bygentle resuspension, and incubated for 10 min at room temperature. Thebeads are pelleted using a magnetic separator, and washed twice with˜250 μL of a buffer comprising 50 mM Tris-Cl (pH 8.0 at 4° C.), 2.5 MNaCl, 20% (w/v) PEG-8000, and eluted by incubating the SPRI beads with12.5 μL of 10 mM Tris-Cl (pH 8.0), 20 mM NaCl. To 12.5 μL of the eluateis added 35 μL RBF, 25 μL LLB (both components of SQK-LSK108, OxfordNanopore Technologies) and 2.5 μL nuclease-free water. This sample isknown as the ‘loading sample’.

An Oxford Nanopore MinION flowcell is primed with 800 μL 1×RBFcontaining 50 nM ‘cholesterol tethers’, bearing complementarity toAR134A and a cholesterol moiety, pipetted via its inlet port, followedby a pause of 10 min, then 200 μL of the same mixture pipetted via itsinlet port with the SpotON port open. The entire 75 μL of the loadingsample was pipetted dropwise into the SpotON port and the fluid allowedto wick into the flowcell. The flowcell is not flushed, and thequantification of target analyte over background is possible becausemembrane tethered analyte is captured preferentially by the nanopore.MinION data collection is initiated immediately, and data are collectedand analysed by counting the number of adapter events.

Results

FIG. 52 shows, in cartoon form, the example described above. Thenanopore sequencing readout is punctuated by a characteristic event L1(which may be basecalled to yield barcode sequence b) that is dependenton the enzyme-loaded adapter C, the frequency of which is dependent onthe concentration of target analyte (membrane-tethered species G, andsolution species H); membrane-tethered species G is capturedpreferentially by nanopore J because of its proximity to the nanopore.Titration of the target analyte (bacteriophage lambda) against theconstant amount of human non-target DNA yields a plot M of the frequencyof event L1 against target analyte concentration. The frequency of eventL1 at zero target analyte concentration (N) demonstrates the‘false-positive’ or background rate of detection of species H capturedfrom solution (i.e., not tethered to the surface).

Materials

DNA and Oligonucleotides

Component name Sequence (Oligos are IDT codes) BacteriophageNCBI Reference Sequence: NC_001416.1 lambda DNA AR134A/5Phos/rCrCrGrArCrCrArCrGrCrCrArGrCrArUrArUrCrGrGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGGTTAAACACCCAAGA OLIGO_2 /5Phos/CTTGGGTGTTTAACCT AR140/5Phos/rUrGrCrArArCrGrGrUrCrGrArUrUrGrCrCrUrGrArGrUrUrUrUrArGrArGrCrUrArUrGrCrUAGCAATACATCTTTG AR131/5Phos/TGTTCTGATCGGAACGATCG/iSp18//iSp18//iSp18//3CholTEG/ AR132/5Phos/CGATCGTTCCGATCAGAACACAAAGATGTATTGCTProteinsONLP12326: S. pyogenes Cas9 D10A/H840A, C-terminal Twin-Strep-tag withTEV-cleavable linker; bold, bracketed shows the portion cleaved by TEV(sequence above).

The invention claimed is:
 1. A system for detecting a targetpolynucleotide in a sample comprising: (i) a nanopore; (ii) anRNA-guided effector protein comprising a guide-RNA binding domain; and(iii) a guide-RNA comprising a crRNA that is complementary to a sequencein the target polynucleotide to be detected and a tracrRNA that iscomplementary to a sequence in the guide-RNA binding domain of theRNA-guided effector protein, wherein the guide RNA or the RNA-guidedeffector protein further comprises an adaptor comprising a leadersequence or an anchor capable of coupling to a membrane.
 2. The systemof claim 1, further comprising a target polynucleotide and a membrane,wherein the nanopore is present in the membrane.
 3. The system of claim1, wherein the target polynucleotide, guide-RNA and RNA-guided effectorprotein form a complex.
 4. The system of claim 1, wherein the targetpolynucleotide is coupled to a surface.
 5. The system of claim 1,wherein the crRNA and tracrRNA are present in a single guide-RNA.
 6. Thesystem according to claim 1 wherein (i) the anchor or (ii) the adaptoris present at the 5′ end of the tracrRNA, the 3′ end of the tracrRNA,the 3′ end of the crRNA, or when the tracrRNA and crRNA are comprised ina sgRNA, the 3′ end of the sgRNA or internally.
 7. The system accordingto claim 1 wherein the anchor is hydrophobic.
 8. The system according toclaim 1, wherein the RNA-guided effector protein is a RNA-guidedendonuclease or a RNA-guided endonuclease wherein the nuclease activityof the RNA-guided endonuclease is disabled.
 9. The system according toclaim 1, wherein one or more of the catalytic nuclease sites of theRNA-guided endonuclease are inactivated.
 10. The system according toclaim 1, wherein the RNA-guided effector protein is Cas, Cas12a orCas13a.
 11. The system according to claim 1, wherein the RNA-guidedeffector protein is Cas9.
 12. A system according to claim 1, wherein thetarget polynucleotide is double stranded or comprises a double strandedregion and is DNA, a DNA/RNA hybrid or RNA.
 13. A system according toclaim 1, wherein the adaptor further comprises a barcode sequence.